Identification of Toolmarks on Furniture
MASTER
’
S THESIS
Student: Welmoed Kreb Student number: 11364769 E-mail: info@welmoedkreb.nl
Thesis supervisor: dr. Herman den Otter Second reader: dr. Tonny Beentjes
University of Amsterdam
Master Conservation and Restoration of Cultural Heritage Specialisation Wood and Furniture
Abstract (English)
Identification of Toolmarks on Furniture, a thesis by Welmoed Kreb in the context of the master’s programme Conservation and Restoration of Cultural Heritage, specialisation Wood and Furniture. University of Amsterdam, August 3, 2020.
This master thesis focusses on the identification of toolmarks on wooden furniture. Techniques and knowledge from several disciplines are combined into identification guidelines for toolmarks that strive to structure and objectify toolmark identification in furniture conservation. The guidelines are substantiated by technical and historical information on the origin of toolmarks and by observations from experienced observers. This combination allows for a deeper understanding of toolmarks and a more profound identification process.
Abstract (Dutch)
Identification of Toolmarks on Furniture, scriptie door Welmoed Kreb in de context van de master Conservation and Restoration of Cultural Heritage, specialisatie Hout en Meubelen. Universiteit van Amsterdam, 3 augustus 2020.
Deze masterscriptie richt zich op de identificatie van gereedschapssporen op houten meubelen. Technieken en kennis uit verschillende disciplines worden gecombineerd tot identificatierichtlijnen voor gereedschapssporen met de bedoeling de identificatie van gereedschapssporen in de meubelrestauratie te structureren en objectiveren. De richtlijnen worden onderbouwd met technische en historische informatie over de oorsprong van gereedschapssporen en met observaties van ervaren waarnemers. Deze combinatie zorgt voor een beter begrip van gereedschapssporen en een grondiger identificatieproces.
Preface and acknowledgements
This thesis about the identification of toolmarks on furniture is written in the context of the master Conservation and Restoration of Cultural Heritage, specialisation Wood and Furniture, at the University of Amsterdam.
First and foremost I would very much like to thank my thesis supervisor, dr. Herman den Otter, for his never ending support, expertise on tools and toolmarks, finding ways to be of assistance and make reconstructions in times of lockdown, for his valuable supply of literature and generously lending it all to me, for proofreading and commenting, for his endless patience and for his faith that I would find my focus in the vastness of the subject.
I thank dr. Marta Domínguez-Delmás (UvA) for introducing the topic of toolmarks to me, helping me on my way and providing very valuable literature.
Furthermore I am grateful to the experts on toolmarks that have generously donated their time and expertise: prof. dr. Harald Bentz Høgseth (Norwegian University of Science and Technology), dr. Hans Piena (Nederlands Openluchtmuseum), Jaap Boonstra (Amsterdam Museum), prof. dr. Jørgen Wadum (UvA), Arnold Truyen (SRAL), Martijn Remmen (Remmen BVBA), Bruno François (Hospices de Beaune) and a very special thanks to Seppe Roels and Marieke van Vlierden (Marks on Art) for their warm welcome into their project for a day and readily sharing all their written and non-written expertise on the documentation of marks.
Also many thanks to the people that were willing to talk along on the topic, the focus, the research and the structure, for sharing their valuable advice and sometimes their contacts with me: dr. Maartje Stols-Witlox (UvA), prof. dr. Maarten van Bommel (UvA), prof. dr. Ella Hendriks (UvA), Kate Seymour (SRAL), dr. René Peschar (UvA), Miko Vasques Dias (UvA), dr. Ineke Joosten (RCE), Saskia Smulders (RCE), Henk Jonker (Jonker Meubelrestauratie), Boudewien Westra (V&A), Jessica Hensel (UvA), dr. Bas van Velzen (UvA).
I’d like to thank my fellow students for their support and acting as sparring partners: Lucas Mantel, Esther Ng Eet Ming, Margot Terpstra and a very special thanks to Sterre van der Weerd and Maxx Folmer for their valuable advice, motivation and support in lockdown circumstances.
And last but not least I want to thank Puk and my friends and family for their support and helping me believe in a life after the thesis.
Table of contents
1 Introduction ... 5
2 What is a toolmark? ... 6
2.1 The mechanics of toolmarks ... 6
2.1.2 Conclusion ...13
2.2 Characteristics of toolmarks ...13
2.2.1 Single marks ...14
2.2.2 Signatures ...16
2.2.3 Multi-stroke marks, kerf marks ...16
2.2.4 Marks specific to certain circumstances ...17
2.2.5 Conclusion ...18
2.3 Tools and production processes ...18
2.3.1 Conversion ...18
2.3.2 The production and application of veneer ...22
2.3.3 Levelling and smoothing ...22
2.3.4 Markings ...24
2.3.5 Clamps and miscellaneous ...24
2.3.6 Joints and constructions ...25
2.3.7 Decorative elements ...26
2.3.8 Conclusion ...28
3 Toolmark investigation ...29
3.1 The focus of toolmark identification ...29
3.2 Detection and examination ...30
3.2.1 What to detect - Characteristics to be discerned ...30
3.2.2 Investigation with and without magnification in combination with different lighting ...30
3.2.3 Measurements ...31
3.2.4 Making impressions and casts ...31
3.2.5 Rubbing and tracing ...32
3.2.6 Comparison to reference samples and reconstructions ...33
3.3 Techniques for documentation of toolmarks ...33
3.3.1 What to document ...33 3.3.2 Verbal descriptions ...33 3.3.3 Drawings ...33 3.3.4 Photographs ...33 3.3.5 Imaging techniques ...34 3.4 Interpretation ...35
3.4.1 Justification of the claim that the toolmark is related to a tool ...35
4 Identification guidelines ...37
4.1 Identification protocols considered ...37
4.1.1 Considerations for the current tool ...37
4.2 Identification guidelines ...38
4.3 Supplement to the identification guidelines ...38
4.3.1 Flat surfaces hidden from view ...38
4.3.2 Surfaces in sight ...48
4.3.3 Veneer ...49
4.3.4 Markings ...49
4.3.5 Joints and construction ...50
4.3.6 Decorative elements ...52
5 Test of identification guidelines ...54
5.1 Examination of the object ...54
5.1.1 Object description ...54
5.1.2 Examination ...55
5.1.3 Results ...55
5.1.4 Conclusion ...56
5.2 Reflection on identification guidelines ...56
6 Conclusion ...58
7 Literature ...59
8 Summary ...61
9 Appendix I – Identification guidelines ...62
10 Appendix II – Manual for identification guidelines ...81
11 Appendix III Examination of object: dovetailed chest ...83
1 Introduction
The identification of toolmarks is one of the methods that is available to the wood and furniture conservator in the research into objects. Toolmarks are defined in this work the traces intentionally or unintentionally left on the surface of an object by woodworking tools or woodworking techniques. Toolmarks are therefore the visible remnants of manufacturing processes. As such, the research into toolmarks can be used for more knowledge about these processes. On the other hand, the use of certain tools can indicate a manufacturing in a certain period or certain region. The identification of toolmarks can therefore assist in dating an object or linking it to a specific region. Traces of tools on an object that were not in use at the time of presumed manufacture can point to restorations, alterations, or even the identification of a fraud.1 This knowledge aids the conservator-restorer in adopting his or her treatment strategy. This research project explores the practice and use of toolmark identification with the aim of optimising the use of this tool.
Although the importance of toolmark identification in the field of wood conservation is recognized,2 information on the identification process is limited and scattered and toolmark description is usually not a standard procedure of the description of objects.3 This seems to imply that identification of toolmarks no longer yields new information, or that the identification of toolmarks is common knowledge for conservators. However the research into toolmarks on Dutch polychrome furniture by wood conservator Hans Piena has not only yielded new information on the manufacturing process of the objects4 but also led to an earlier presumed use of the circular saw in Dutch cabinet making.5
In the wood conservation literature information on toolmarks is often just a mention of an identified tool. Other literature in the field of furniture conservation is the result of assessments of a body of similar objects, such as the already mentioned research, the research into 18th century Liege furniture6 or 17th and 18th century German furniture,7 where toolmark investigation is used to gather insight into manufacturing processes. These works also address the subject of the identification process. Another body of texts that deal with toolmark identification on furniture are works aimed at buyers of antiques to guide them through the slippery realms of the antique trade. This literature is based on the experience of the writers in the antique trade and or with making frauds themselves,8 of which an early example is the 1929 book by antiques forger André Mailfert. The toolmark identification is aimed at discerning the difference between genuine objects and objects that are modified or made as frauds.
A field outside of furniture conservation that makes use of toolmark identification is the field of forensics. The aim of the identification is tracing the marks of a crime scene back to an individual specimen of a weapon or a tool. Because of its use in court the toolmark identification is executed via strict protocols and with selected materials and equipment.9 Toolmark investigation also plays a large role in archaeology for determining unknown production processes. In experimental archaeology reconstruction work is combined with toolmark investigation for the reconstruction of prehistoric or other woodworking processes. This comparison of toolmarks of reconstructions to toolmarks of a find can reveal many details about the working processes. It is reported to be possible to identify the working procedure and order, position of the craftsperson in the various stages of the work, the shape and weight of the tool, the length of the shaft, and whether the wood was green or dried10. In the research into Medieval panel paintings and polychrome
1 Piena, Beschilderd, 135.
2 Rivers and Umney, Conservation, 386. 3 Schindler, “Formspuren,” 425.
4 The pit saw seems hardly to have been used for the manufacturing of Dutch polychrome furniture in the period
from 1650-1930. Piena, Beschilderd, 137.
5 Hans Piena, telephone conversation with author, June 11, 2020. 6 Bernard, Étude.
7 Schindler, “Formspuren.”
8 Mailfert, Pays, 8; Hayward, Antique, 8. 9 Chumbley, Quantification, 8.
sculpture, toolmark recognition is used for more information on the production process11 and has also led to ascribing different objects to an individual workshop.12
It would seem that in fields where the number of methods of gathering information on manufacturing processes is more limited than in furniture conservation, toolmark identification is taken to a higher level. More techniques for recognition are employed and more information on the objects is found. The aim of this work is to find out whether the insights and knowledge from the sources on furniture can be combined with insights from other disciplines to optimise the toolmark investigation in the field of wood and furniture. The research question of this thesis is the following:
How can toolmark recognition in the field of wood and furniture conservation be executed
and optimised, and what information on the objects can this provide?
The practical result of this research will be a set of guidelines for toolmark investigation that will be a combination of the insights of the various disciplines. The developed guidelines will be tested for efficacy on a case study, selected on grounds of expected different toolmarks. The guidelines will be adjusted if needed. This work focuses on toolmarks in the period from the 17th to the early 20th century. Only toolmarks left on wooden surfaces will be covered. Marks on other materials and on finishing layers are not addressed. The objective of this research is to provide the research into toolmarks on furniture with more structure, technical substantiation and ways for verification. Thus it is hoped toolmark recognition in furniture conservation will not only become more standardized, but will also lead to more knowledge on toolmarks through the opportunity of verification and comparison, and might eventually lead to more knowledge on production processes and maybe even to ascribing two pieces of furniture to a particular workshop.
2 What is a toolmark?
In this chapter I will explore the nature and appearance of toolmarks. First the technical background of woodworking actions will be explained and how these actions are reflected on the surface of the wood. The appearance of toolmarks and their characteristics will be defined into definitions that allow meaningful discourse about them. Finally an overview will be provided of woodworking tools and practices that were in use in the period from the 17th to the 20th century and that can be expected to have left their traces on the furniture of this period.
2.1 The mechanics of toolmarks
This paragraph describes the different factors that determine how and when woodworking tools leave their marks on the wood.
2.1.1.1 The strength of wood
Changing the dimensions of wood with a tool is a subtractive operation. Pieces of wood are removed to arrive at the desired shape. To remove material, damage needs to be inflicted to the wood in a stress-failure procedure.13 Stress is defined as a force, or load, acting on a unit of area.14 A moderate load applied on a very sharp blade (a small area) will result in considerable stress. Stress will first result in deformation of the material, known as strain. Within its so called elastic range, wood is able to fully recover from this deformation. If stress is applied outside of this range, beyond the so called proportional limit, part of the strain becomes permanent.15 Pounding a hammer lightly on a surface causes strain. If this strain remains
11 Wadum, “Historical,” 153; 11 Truyen and Seymour, “Traces,” 3. 11 Kate Seymour, conversation with author, February 20, 2020.
12 Wadum, “Historical,” 153-154; Kate Seymour, conversation with author, Februari 20, 2020; Høgseth, Language, 97. 13 Hoadley, Understanding, 159.
14 Ibid, 75.
within the elastic range the wood recovers and the hammer will not leave an impression. A hard blow however might permanently dent the wood. When above the proportional limit even more stress is applied this can finally result in failure of the wood.16 The basic stresses that can be applied to an object are compression, tensile and shear stress.17
The ability to resist applied stress is expressed in the strength of the wood.18 As wood is an inhomogeneous and anisotropic material, the ability to resist stress is not equal in all directions or throughout the entire material. For all species the compression, tensile and shear strengths of wood are much larger in the longitudinal direction than in transversal direction.19 In some wood species the difference between radial and tangential strength is also considerable.20 Large rays for instance mean a structural weakness in wood.21 There can also be a difference in strength between earlywood and latewood in several wood species.22 In ring porous woods or in some softwoods the earlywood is considerably soft.23 Moisture content too plays a role in strength. The higher the moisture content, the weaker the wood. Green wood is therefore much less strong and more easily worked than seasoned wood.24
The difference in compression strength between the longitudinal and transverse direction for instance explains why a blow with a hammer will make a deeper mark on a longitudinal plane than on a transversal plane. The process of riving (splitting) makes use of the difference in tensile strength between the longitudinal and the transversal direction. Riving involves a tensile stress in a transversal direction which will sever the fibres along the grain. It works best in the radial plane for wood species with large rays such as oak25 and will work better for wood species with straight grain instead of interlocked grain.26 2.1.1.2 The blade
It is usually the cutting edge of a cutting tool that applies the compression, tensile or shear stress on the wood. It is amongst other things the cutting angle (also rake angle) that determines which kind of stress is applied. The cutting angle is the angle between the front surface of the blade and the sole behind it.27 In a plane this angle is often 45°,28 in a cabinet scraper this angle could be over 90°.29 Figure 1 shows the related angles of a cutting tool. The angle between the face and the back of the blade is the sharpness angle. Figure 2 shows an idealised cutting action where the force applied on the cutting edge results in tension stress and failure in the form of severed fibres.30 Figure 3 shows a cutting action where also the strain (deformation) and the partial spring back of the wood after failure are taken into account. It is important to keep the failure of the wood close to the blade to ensure a clean and controlled action. Riving is an example where the failure occurs well before the blade and the shape and surface quality of the chip cannot be controlled.31
16 Ibid. 17 Ibid, 78. 18 Ibid, 76.
19 Rivers and Umney, Conservation, 83. 20 Hoadley, Understanding, 81. 21 Ibid, 22.
22 Ibid, 78. 23 Ibid, 81.
24 Rivers and Umney, Conservation, 86. 25 Hoadley, Understanding, 22. 26 Ibid, 29 27 Sterre, Schaven, 24. 28 Hoadley, Understanding, 162. 29 Ibid, 163. 30 Ibid, 160. 31 Ibid, 161.
Figure 1. The cutting edge of a cutting tool. Image after Hoadley, Understanding, 160.
Figure 3. Cutting action showing strain and partial spring back. Image: Hoadley, Understanding, 161.
With a lot of tools such as different kinds of planes the cutting angle and the depth of cut are a constant, determined by the tool design.32 With tools like chisels, adzes and drawknifes the cutting angle and depth of cut are determined by the movement of the operator.
2.1.1.3 Woodworking actions explained 2.1.1.3.1 Planing parallel to the grain
The process of planing starts with the blade separating a part of the wood structure, thus forming the beginning of a chip.33 Figure 4. The chip slides up the blade which causes tension stress in perpendicular direction, causing the chip to tear further in front of the blade until the bending stress is too high and the chip fails in a crack across the grain. The blade then advances to this crack and the process will repeat itself.34 To avoid too much lifting of the chip that results in an uncontrolled tearing of the grain ahead of the blade, the chip needs to be broken rather sooner than later. To help break the chip near the blade, an extremely thin chip can be taken or the plane can be fitted with a cap iron.35 The situation as depicted in the figures is the situation under the conditions of straight grain, where the grain runs perfectly parallel to the direction of the cut. Usually however there will be some level of cross grain, where the grain either slopes up or down before the blade. In the first instant, the action will be cutting along the grain, in the second case, it is cutting against the grain. Cutting against the grain will often result in uncontrolled splitting and chipped or torn grain.36 32 Hoadley, Understanding, 165. 33 Ibid,160. 34 Ibid,162. 35 Ibid,164. 36 Ibid,163.
Figure 4. Cutting action of a handplane. Image: Hoadley, Understanding, 162.
2.1.1.3.2 Scraping
With a large cutting angle, as is the case with using a scraper, the fibres will not be severed by an inserted blade but mainly compressed by the advancing blade in the longitudinal direction which results in shear. Figure 5. This action will only produce a smooth surface when a very small chip is taken, otherwise the compression will cause uncontrolled failure and leave an irregular surface.37 An imperfect scraping or planing action can cause chatter marks.38
37 Ibid,163. 38 Ibid, 199.
Figure 5. Cutting action of a scraper that involves compression of fibres. Image: Hoadley, Understanding, 163. 2.1.1.3.3 Cutting across the grain
The fibres are less strong across the grain in tensile strength and more easily torn out in planing across the grain. This property can be used for quick removal of material.39 Interlocked or cross grain that might be torn out anyhow by planing along the grain can also be planed across the grain.40
A special case of cutting across the grain is veneer cutting.41 In this case the chip needs to be left intact because this will be the veneer. The veneer will risk the same cracks at the back as the chip of planing mentioned above. These small cracks in veneer are known as knife checks. Knife checks are more of a problem in veneer over 3 mm thickness, but can be minimized by optimizing the production process.42 Figure 6
Figure 6. Process of veneer slicing. Left knife checks can be seen. At the right the process is optimalised. Photos: U.S. Forest Products Laboratory
39 Ibid, 170. 40 Ibid, 170. 41 Ibid, 169. 42 Ibid, 169.
2.1.1.3.4 Planing end grain
For planing end grain the fibres need to be cut across the grain, in which direction they are strongest. In this process the fibres are bent and displaced by shear before failure. In case of a dull edge, a high cutting angle or if a thick chip is taken, the fibres will be seriously deformed and displaced by compression perpendicular to the grain.43 Typically end grain planes have a low cutting angle of about 35°.44
Figure 7 Endgrain cut with a cutting gouge, upper, and with a marking gouge with nail, under. The cutting gouge makes a clearer cut. Photo: WK 2.1.1.3.5 Sawing across the grain
In sawing the teeth need to create a path for the width of the blade, the saw kerf. The teeth need to be able to cut the fibres in the longitudinal direction at both sides of the kerf and remove the severed material from the bottom of the curve.45 To cut wood across the grain, the teeth are usually sharpened to form small knives on both sides of the blade46 and they must have set, they are alternately bent a little outward, so that the saw kerf will be a little wider than the blade to prevent friction and clogging of the blade in the kerf.47 2.1.1.3.6 Rip sawing
Also in rip sawing, the saw has to create a path for itself. In this case it is not the fibres of the kerf walls that pose most of the problem as they will shear easily. It is the fibres at the front of the blade, the bottom of the kerf that need to be cut across. The saw teeth of a ripsaw therefore need to have their cutting edge at the tip. So although the saw blade as a whole travels in longitudinal direction, the cutting edges of the teeth work across the grain.48 Also saws are made that are a combination of rip and crosscut saws.49
2.1.1.3.7 Sanding
When abrasive paper is viewed under magnification it can be seen that it exists of a series of crystals glued onto a carrier. The crystals form ‘blades’ with large cutting angles, they will therefore perform a scraping action rather than a cutting action.50 Sanding is as much as possible performed parallel to the grain. Sanding across the grain is very much advised against, since it will leave broken out cell walls which can cause an uneven uptake of finish for instance.51
43 Hoadley, Understanding, 168. 44 Greber, Geschichte, 203. 45 Hoadley, Understanding, 171. 46 Ibid, 172. 47 Ibid, 168. 48 Ibid, 168. 49 Ibid, 172. 50 Ibid, 200-1. 51 Ibid, 200.
Figure 8. Traces of abrasives that show in a darker colour. Walnut early 20th century bed. Photo: WK. 2.1.1.3.8 Rotary actions
In rotary actions such as drilling, circular sawing or machine planing the blade works the wood at alternating angles. Drilling perpendicular to the grain for instance will result in an action that is alternately along and across the grain. In a planer the rotating blades nip curved chips from the surface in an action that approaches that of planing along the grain. The undulating toolmarks of a planer are known as knife marks. A rate of feed that is too slow will cause the blades to scrape instead of cut, which will result in compression and a polished surface.52 When the blade of a circular saw is set high and the teeth approach the wood from above, fibres can be cut cleanly across. When using the circular saw at a low position to cut a groove, the blade is used at its top, which leaves a more ragged surface.
2.1.2 Conclusion
From this overview it can be derived that for the resulting damage from a tool on the wood a few factors are of importance. Fibres are permanently compressed when the stress applied surpasses the proportional limit for the wood species and the plane it is applied on. For surfacing actions like planing, scraping and sanding the cutting angle determines the thickness of the chip that can be taken and the quality of the surface. For all actions working along the grain will leave the smoothest surface, but sometimes working across the grain is inevitable. Working across the grain and against the grain will risk fibres tearing out. Apart from the cutting actions, the factors that can influence the damage of a tool are wood species and its properties, early- or latewood, orientation in the trunk and moisture content.
2.2 Characteristics of toolmarks
For communicating about toolmarks it is important to set a few definitions. As toolmark identification is further developed in the fields of archaeology and forensics, some terms and definitions from those fields are introduced. In forensics, toolmarks are defined as follows: “Toolmarks are impressions or marks that are produced by a tool or instrument on a receptive surface.”53 The area of the tool that comes in contact
52 Ibid, 165.
with the other material to make a mark is called the working surface of the tool.54 In the case of a plane only the part of the blade that protrudes beyond the sole is part of the working surface, but also the sole itself, as it can also leave traces.
2.2.1 Single marks
In forensics two major types of marks are discerned. When force and motion of the tool are predominantly perpendicular to the surface, an impression or impressed mark will be created.55 Examples of this on furniture are the indentation of a clamping device in the wood, decorative punch marks or a hammer blow. The other type of mark is caused when force and direction of the of the tool are predominantly parallel to the surface. In woodworking this can be the result of a planing, a scraping or a cutting action. If the tool has imperfections on its working surface such as dents or bumps, these imperfections leave traces of parallel lines of ridges (in the case of dents) or grooves (in the case of bumps) on the surface. These lines are known as striations56 and the resulting mark as a striated mark..57 An example of this are the fine lines left by a stroke of a plane or a gouge over a surface. Figure 9.
The mark resulting from one blow or one uninterrupted movement of a tool will in this thesis be referred to as a stroke, in the case of the oblong marks of a plane, or a facet, in the case of the shorter marks of axes and adzes.58 The stroke has three characteristic parts. The already mentioned striations are one of them. When also the sides of the tool are reflected in the mark, these are called the side features. When the working surface of the tool comes to a halt in the material at the end of the movement, this is reflected in the mark as the stop line.59 As the action comes to a halt, wood fibres can be left on the upper side of the working surface, in the form of a small flap over the tool. This flap is known as jam wood.60
Figure 9. Single stroke mark that was worked from right to left.
54 Chumbley, Quantification of Toolmarks, 6. 55 Ibid. 56 Ibid. 57 Gallagher, “Toolmarks.” 58 Allen, “Illustration,” 4. 59 Ibid. 60 Høgseth, “Language,” 96.
Very often marks are not complete. A scraper that works a surface can leave striations but often the edges of the blade will not show itself in the mark, nor will stopping points often be visible as the blade usually gradually exits the wood without jamming into it. When the side feature and the stop line do show, these will yield information about the tool. A complete stop line can be measured to determine the width of the tool.61 The striations show the trajectory of the tool along the surface ending at the stopping point. The angle between the striations and the stopping point indicates the angle in which the tool was used. This angle will be referred to as the working angle. From Figure 9 it can also be deduced that the distance between the side features of a mark does not necessarily reflect the width of the working surface of the tool as it can have been used at an angle. Only a complete stopping point will show the true width of the working surface. For sawing the term working angle will be used for the angle at which the blade was held toward the direction in which it is used. In a band saw, the working angle will be fixed at 90° by the design of the machine. When jam wood is present, it might indicate the shape of the tip of the tool and the sharpness angle.
Figure 10. Striations resulting from a woodworking action in relation to the angle of the tool. Image: Sands 1997, taken from Høgseth, Language, 97.
Figure 11. The relation between the toolmark and the cutting angle of a tool. Image: Høgseth, Language, 97.
2.2.2 Signatures
The imperfections in material and manufacturing processes combined with traces of wear or grinding, set the working surface of a specific tool apart from other tools from the same make, and a toolmark from that particular working surface reflects these imperfections resulting in a toolmark which is believed to be unique for that specimen.62
A unique striated toolmark is known as the signature of the tool.63 The signature is the combination of all ridges or grooves in a striated mark. Note that the signature of a tool can alter completely as a result of wear, damage or grinding. When several incomplete signatures of the same tool are present on an object, it is possible to reconstruct the minimal width of the blade by adding up parts of the signature. When signatures of the same tool are found on different objects, these objects were worked at by the same tool.64
2.2.3 Multi‐stroke marks, kerf marks
A lot of woodworking actions involve repetitive action on nearly the same location on the object, such as sawing, sanding, drilling or turning on a lathe. This repetitive action on one location causes a stroke to be overlapped or eradicated by the next, so that single strokes are no longer recognizable as such. The marks resulting from repetitive action are called multi-strokemarks.65 Figure 1212. When made by a saw they are also referred to as kerf marks.66
Figure 12. Multi-stroke mark or kerf mark of a hand saw on pearwood.
In woodworking, toolmarks very often are the result of a working process consisting of numerous successive actions. In carving for instance strokes often do not entirely overlap, and single strokes can still be identified. Nevertheless the set of strokes can be a characteristic display of a woodworking action or practice. This collection of single strokes will be called a stroke pattern. 13. In the stroke pattern not just the tool but the characteristics of the operator will be expressed. This characteristic stroke pattern that is made by a craftsperson will in this work be referred to as the handwriting of the stroke pattern. It can be imagined that training, skill, physical strength and personal preference can influence a stroke pattern. It might also be possible that different wood species lead the operator to choose another technique, thus also influencing the stroke pattern. Although it is generally acknowledged that a signature can be unique to a tool, for the handwriting this uniqueness cannot be established. It is however possible to discern certain characteristics in handwritings, for instance whether the operator was a skilled worker or a novice.67
62 Chumbley, Quantification of Toolmarks, 7. 63 Høgseth, “Language,” 96.
64 Allen, “Illustration,” 4. 65 Gallagher, “Toolmarks.” 66 Williams, “Reading,” 108.
Figure 13. Stroke pattern mark of a roughening plane. Photo: Hans Piena.
2.2.4 Marks specific to certain circumstances
Certain circumstances can sometimes result in side effects from wood working actions that will not always occur when a tool is used. Tear out marks , or tear outs68 can be an unwanted side effect of sawing, drilling and working with chisels, gouges and planes, or a result from working across the grain. Chip marks can be the result of the use of a planer.69 Woolly grain can result from working tension wood or wood with a high moisture content.70 Several actions can induce resonance in the blade, which can result in chatter marks. In paragraph 2.1 the causes for some of these marks are further explained. Figure 14.
Figure 14. Mark of a plane on spruce, planed against the grain. Tear outs and chatter marks show. Photo: WK.
68 Hoadley, Understanding, 199. 69 Ibid. 168.
Often different tools are used subsequently on one location. This can result in marks that bear the traces of both tools which can be confusing. Especially when the first tool had a deeper effect in the wood and the second tool a more superficial working, the location can bear traces of both.
2.2.5 Conclusion
In this section the most important characteristics of toolmarks have been covered that can be used to discern between the various appearances of marks. In the next section a few of the most important tools and manufacturing processes are covered that produce these marks.
2.3 Tools and production processes
As toolmarks are the physical reflection of woodworking processes, identifying toolmarks has a close relationship to the history of woodworking. Knowledge of practices and tools in a certain timeframe will aid in identification. Therefore in this paragraph a concise overview of woodworking procedures from the 17th century to the 20th century is provided. As hundreds of woodworking tools exist, this survey can only be very rudimentary and is far from exhaustive. Tools are covered that are often reported in toolmark recognition and tools that have changed over the course of the ages. The focus is on processes used in Dutch cabinet making.
This survey is structured along the various objectives of woodworking: conversion, levelling and smoothing, construction and decorating techniques.If time frames are indicated, it must be realised that in rural area’s some techniques have persisted much longer than in industrial areas, where they have been replaced with newer techniques from an earlier date. The knowledge about when a tool first came into use is sometimes also based on toolmark research, so more detailed research may revise these dates.
2.3.1 Conversion
Conversion is the general term to indicate the process that divides the trunk into smaller parts that can be used for further working.
2.3.1.1 Splitting/riving
Riving is a simple and quick method to divide a trunk into boards. To initiate the split a series of large iron wedges can be inserted with a hammer and for smaller parts a froe and hammer can be used.71 Oakwood is easily radially split along its large rays, but uneven grained species like elm wood is usually sawn.72 Edwards Encyclopaedia of Furniture Materials, Trades and Techniques indicates that riving was mainly used in the 16th and 17th century but that it remained popular for centuries after.73 Piena finds that riven boards can be found in Dutch furniture until 1630.74
2.3.1.2 Pit saw
Pit sawing gradually replaced riving. The trunk was either positioned over a pit or placed on one or two trestles and the sawing was done by two man, one on top of the trunk and one underneath.75 The teeth of pit saws were set wide76 to avoid clogging of the saw in the kerf. The saws that were used could be a frame saw and an open saw. The blade of the frame saw was usually of narrower width than that of the open large whip saw, that had reportedly a larger accuracy.77 Pit sawing was from the start of the 17th century in the western part of the Netherlands quickly replaced by windmill sawing and traces of a pitsaw are not much
71 Edwards, Encyclopedia, 180. 72 Hayward, Antique, 23. 73 Edwards, Encyclopedia, 67. 74 Piena, Beschilderd, 135. 75 Janse, Aaks, 50. 76 Bernard, Étude, 45. 77 Piena, “Afgezaagd,” 14.
encountered in Dutch furniture, and if then in furniture made from locally grown woods.78 In some countries and regions pit sawing continued until well into the 19th79 or even up into the 20th century.80 Figure 15.
Figure 15. A demonstration of pit sawing. Photo: Collectie Nederlands Openluchtmuseum. Inv.nr.: AA 11150.
2.3.1.3 Sawmill
Sawmills mechanise the sawing process. They are powered either by man, animals, water or wind. The sawing involves a reciprocating movement of the saw(s) mounted in a frame. The first water powered saw mills had a camshaft for transferring the rotating movement into a reciprocating one, but the combination of the crankshaft with wind powered mills around 1600 totally and quickly transformed the Dutch timber production. By 1630 practically all wood conversion in the western part of the Netherlands was done by wind sawmills.81 In a saw mill the feed is usually automatically controlled by the sawing operation but the rate of feed could (also during sawing) be adjusted to wind speed and wood species and the desired result. Wood was sawn when wet.82 In the Netherlands from 1837 on the different sawmills gradually were converted to steam sawmills, and new steam sawmills were erected. This resulted in a constant rate of
78 Piena, Beschilderd, 137-8.
79 Edwards, Encyclopedia, 67; Hayward, Antique, 80. 80 Bernard, Étude, 48.
81 Piena, Beschilderd, 135. 82 Piena, “Afgezaagd,” 16.
propulsion and feed and less backlash.83 In the Netherlands wood was also imported during the 16th to 20th century, so saw marks can also be the result from foreign ways of conversion.84Figure 15Figure 16.
Figure 16. Interior of wind sawmill with sawframes. Photo: Collectie Nederlands Openluchtmuseum. Inv.nr.: AA 8075.
2.3.1.4 The bandsaw and mechanisation of workshops
The bandsaw no longer works with a reciprocating movement but with a continuous. From the course of the first half of the 19th century the industrial bandsaw was of that level that it could be used to convert lumber on a considerable scale. In the Netherlands traces of it are mostly found from 1900.85
In workshops smaller bandsaws are used and can be used well for contoured parts. Marquardt mentions it in general use from the second half of the 19th century.86 The bandsaw is presumed to have been used in furniture making in the Netherlands from around 1880.87 Figure 17.
83 Piena, Beschilderd, 142.
84Piena, “Afgezaagd,” 13.
85 Piena, Beschilderd, 144. 86 Marquardt, Original, 110. 87 Piena, Beschilderd, 148.
The introduction of machines first in conversion and later in cabinet making was a process of decennia that started at the late 18th century.88 During most of the 19th century this was dependent on steam power. As a steam engine was a large investment and was only profitable in a large continuous production, the use of it was restricted to large factories, and in the Netherlands only from the second half of the 19th century. Only with the introduction of gas or diesel engines at the end of the 19th century and electrical engines in the early 20th century, smaller workshops start having machinery.89 Processes could however also be mechanised by using hand or foot power. The jigsaw, a reciprocating frame saw with a narrow blade was developed in the late 18th century. The foot-operated jigsaws from the 1860’s are reported to have made intricate shaped furniture widely accessible in the later 19th century.90
Figure 17. Bandsaw. Image: Machines à travailler le bois. Auxerre (Yonne): Guilliet & Fils, 1906, p. 60 2.3.1.5 Circular saw
Large steam powered circular saws were employed in conversion from the early 19th century.91 In cabinet making workshops the circular saw is used for ripping, cross cutting and mitring. In Germany and the UK the circular saw came into general use in cabinet making from the second half of the 19th century,92 in the Netherlands this was probably later.93 Edwards suggests the use of treadle operated circular saws in small workshops in the UK from the later 19th century that seriously influenced the furniture production of small workshops.94
2.3.1.6 Handsaw
Handsaws were used in the entire period covered in this work. Even when machines are present, for a single cut a handsaw can be a quicker solution. The handsaw was reportedly mainly used by furniture makers to adjust the dimensions of wood bought from sawmills or pit sawyers. Dutch sawmills supplied such a variety of different widths and thicknesses that rip sawing was probably hardly ever needed and the hand saw was mainly used for cross cutting.95 For sawing curves usually a frame saw with a narrow blade was used.96
88 Edwards, Encyclopedia, 127. 89 Piena, Beschilderd, 158. 90 Edwards, Encyclopedia, 189. 91 Edwards, Encyclopedia, 67.
92 Marquardt, Original,109; Hayward, Antique, 81. 93 Van Voorst tot Voorst, 1992, via Piena, Beschilderd, 150. 94 Edwards, Encyclopedia, 66.
95 Piena, Beschilderd, 139-140.
2.3.2 The production and application of veneer
Veneer can be made in various ways. Traditionally veneer is sawn with a two person frame saw, the wood clamped in an upright position. The veneer that was sawn in this manner could be as thin as 2,1-2,8 mm thick.97 In the 18th century already some mechanisation of frame sawing veneer was realised.98 From the start of the 19th century in the Netherlands veneer saw mills were in business, powered by man, horse or wind and later by steam. The teeth were designed to saw in both directions. Steam powered circular saws were in general uses from around 1840. The diameter of these circular veneer saws were typically very large, up to 6 meters. The teeth had a very narrow set.99 From the start of the 19th century it became possible to slice veneer, in this process the veneer is cut instead of sawn. Firstly only relatively soft and straight grained wood could be sliced.100 The next process was rotary cutting, where the veneer is cut from a rotating log which makes it always a tangentially cut. This process is presumably not widely used until late in the 19th century.101 All processes are still used, the reciprocating sawing of veneer is on a small scale still used for expensive veneers.102 Also a bandsaw can be used for sawing veneer.
Veneer is traditionally laid by pressure from a heated caul. The caul can be made of wood to the shape of the substrate or sandbags or lead weights can be used. Veneer can also be laid by applying a veneer hammer. The hammer can only be used on simple, flat work with pliable veneers, and not on marquetry. These methods were used since the 17th century103 and the process of heated cauls is still used today, and occasionally the use of the hammer as well.104
2.3.3 Levelling and smoothing
2.3.3.1 Axes and adzesAxes, or side axes, have been used to square trunks into baulks, remove sapwood and level riven boards. Piena reports traces of the use of side axes on Dutch furniture dating between 1650-1730.105 Wadum indicates 16th and 17th century Low Countries panel paintings to have been mostly levelled by planes, scrapers and only rarely by small axes.106 Adzes are also used for levelling and smoothing, either along the grain or across. After an adze also an (broad) axe can have been used for further smoothing along the grain.107
2.3.3.2 Planes
For further levelling and smoothing often planes have been used. For rough work often a plane was used with a convex iron.108 The sole could be flat109 or also convex.110 A plane removes a chip the thickness of the protruding part of the iron.111 Piena indicates 17th and early 18th century marks of the roughening plane to be deeper and narrower than those in the course of the 18th century.112 For finer work usually a smoothing plane with a flat sole is used. For longer surfaces planes have been designed for preparation and for finishing work that have much longer bodies than normal planes.113
97 Piena, “Afgezaagd,” 19. 98 Hayward, Antique, 81. 99 Piena, “Afgezaagd,” 19. 100 Piena, “Afgezaagd,” 20. 101 Edwards, Encyclopedia, 233. 102 Piena, “Afgezaagd,” 20. 103 Edwards, Encyclopedia, 234. 104 Hayward, Antique, 202. 105 Piena, Beschilderd, 136. 106 Wadum, “Historical,” 153. 107 Williams, “Reading,” 107-8.
108 Schindler, “Formspuren,” 437; Piena, Beschilderd, 153. 109 Williams, “Reading,” 111; Greber, Geschichte, 204. 110 Piena, Beschilderd, 153.
111 Janse, Aaks, 58. 112 Piena, Beschilderd, 153. 113 Janse, Aaks, 58.
The cutting angles of planes are varied according to their purpose. An angle of 45° is used for removal of material, and for finer work an angle up to 65°. The final smoothing can be executed with a cabinet scraper that works at a very high cutting angle, around 90°, and that is used either in a jig or loose.114 For planing end grain the cutting angle needs to be smaller, for instance 35°. Figure 18.
For working difficult grain, a large cutting angle can be used.115 Also a cap iron will leave a smoother surface with less tear outs on difficult grain or at knots. A cap iron is encountered from 1760.116 A toothing plane is also used for levelling difficult grain without causing severe tear outs. Toothing planes were often used for undersides of furniture or undersides of veneers and preparation of the carcass to be veneered.117 For working curved surfaces planes have been designed with soles that are either convex or concave in length.118 For planing recesses a router plane can be used that has an iron that protrudes far below the sole.119 The levelling process was mechanised by the planer. From the second half of the 19th century the planer was more and more used.120
Figure 18. Cabinet scraper. Photo: Williams, "Reading," 115.
2.3.3.3 Rasps, files and abrasive materials
Rasps and files can be used for removing material and for smoothing. Their section can have curved or angular shapes, for selective use on different surfaces, and they can therefore be used on uneven surfaces or in bores.121 Abrasive materials are used in the final stages of cabinet working to erase traces of other tools and to smooth or polish the surface. A lot of materials can be used and the following summary is not exhaustive. Abrasive materials can consist of a finely divided material either used loose or in a mixture, or glued to a backing. As finely divided materials brick dust, pumice, ground glass or sand could be employed, as backings paper or cloth, and they can be used in mixtures of for instance oils or varnish.122 Other materials
114 NN, “Identifying,” 101. 115 Greber, Geschichte, 203. 116 Salaman, Dictionary, 299. 117 Williams, “Reading,” 111-2. 118 Janse, Aaks, 75. 119 Bernard, Étude, 56. 120 Hayward, Antique, 82. 121 Janse, Aaks, 55. 122 Edwards, Encyclopedia, 1-2.
can be used as they are, such as fish skins123 and equisetum124 that were both widely used until into the 19th century125 or pieces of wood for finishing turned work.126 From the 1870’s sanding machines with drums or belts were developed.127 Next to that also orbital sanders are used.128
2.3.4 Markings
Markings can have different functions on furniture. Boards can have been marked in the wood trade or transportation. These marks are often made with an awl knife or scribe.129 The most commonly encountered marks are those used in constructions. For the alignment of mortise and tenons presumably often a marking gauge is used that makes use of a fence to cut or scratch a line parallel to one of the edges of the work.130 Scratch lines have been found on furniture from the mid-17th century until the early 20th century.131 Marking lines can also be made by a pointed pen or awl along a square, ruler or bevel, or fitted to a stick to use as a marking gauge along a wider distance. Compasses can be fitted with sharp points to set out circular shapes. Marking lines can be used for indicating parts of the construction or design, such as for the location of nails or under marquetry or for carved design.
Other marks are used for indicating locations of parts in the object, such as assembly markings and numbers on drawers.132 Signs of alignment are usually put on outside surfaces and erased in the process of smoothing.133 Red crayon on inside or back surfaces is reportedly used in Dutch furniture for indications of location from the late 17th century.134 Bernard mentions red and black crayon to be used in the 18th century.135 Blue crayon is used from the 19th century. From the late 18th or early 19th century graphite markers and later pencil are used.136
2.3.5 Clamps and miscellaneous
Clamps can have been used in conversion and in further woodworking processes. For securing wood in saw mills large iron clamps or pointy iron pincers were used.137 For securing work on a workbench clamps can be used but also a vice, bench dogs or a construction with wedges.138 For securing carving work on the bench also a bench screw was used,139 or a construction similar to that of a lathe.140 The work is not necessarily clamped, also a ridge can be used where the work is rested against while working the wood.141 Clamps can have be used for gluing. Originally glue clamps were made of wood. Since the second half of the 19th century also glue clamps of iron are in use.142
Hammers are used for inserting nails, sometimes in combination with a punch. The use of the punch is mentioned in the second half of the 18th century.143 Early hammers were of soft iron, and had rounded edges to avoid losing their shape. From the 19th century hammers could also be from hardened steel.144 For
123 Ibid. 1. 124 Ibid. 95. 125 Ibid.1; Ibid.95.
126 Herman den Otter, conversation with author, July 16, 2020. 127 Edwards, Encyclopedia, 1. 128 Williams, “Reading,” 115. 129 Janse, Aaks, 61. 130 Bernard, Étude, 56. 131 Piena, Beschilderd, 152. 132 Piena, Beschilderd, 153. 133 Bernard, Étude, 60. 134 Piena, Beschilderd, 152. 135 Bernard, Étude, 60. 136 Piena, Beschilderd, 152. 137 Piena, Beschilderd, 141. 138 Janse, Aaks, 89. 139 Edwards, Encyclopedia, 20. 140 Truyen and Seymour, “Traces,” 2. 141 Janse, Aaks, 53.
142 Ibid. 88. 143 Ibid. 61. 144 Ibid. 60.
the removal of nails pincers can have been used or several tools fitted with a claw. Pincers and a claw hammer have been in use since Roman times.145
2.3.6 Joints and constructions
Joints such as dowels or pegs, dovetails, mortise and tenon and nails have been used in the entire period this work covers. Hayward mentions that the tools used in making joints are usually the most basic joints every journeyman possessed.146 For using pegs or dowels a drill is needed and pegs are often riven and refined by a chisel. 147 Dowels are more often used during the second half of the 19th century to replace mortise and tenon. These dowels are often rounded by hammering them through a dowel plate.148 Boards can also be joined by nails. When nails are used often the holes are pre drilled.
Dovetails are sawn and or chiselled, so are tenons. Mortises can be partly drilled and chopped by a chisel or mortise chisel aided by a hammer. The bottom of mortises can have been levelled by a router plane or a chisel with bent iron.149 When the mortise and tenon are pegged, also a drill is needed.
For joining boards side by side the butt joint, rebate or tongue and groove joint can be used. For a glued butt joint the surface needs to be accurate, and preferably a plane is used with a straight blade and long sole.150 For making rebates, tongues and grooves specialised planes can be used that are made or can be adjusted to the desired width and depth.151 Often these planes are equipped with a fence to ensure the rebate or groove stays at a constant distance from the side and make a constant depth. For working across the grain the grain can first be cut, or the plane can be equipped with a knife for that purpose to avoid tear outs. Piena indicates that often boards with tongue and groove were directly purchased from the sawmill.152 Schindler reports that also marks of chisels,153 saws,154 or router planes155 are found inside of grooves, indicating their use next to or instead of planes. When the circular saw became common it could also be used for making grooves and rebates. Mortising machines where invented in the early 19th century for large production work, but reportedly only until much later used in cabinet making.156 Joints need no longer be marked in advance157 because the machine process also encompasses the alignment of parts.
Drills are used for construction purposes, such as for pegs, dowels, nails and screws and for attaching large turned pieces. They are also used for preparing carving and decorative work. A drill with a brace was presumably in use from the 14th century and could be used for holes with a diameter of up to 5 cm.158 The nail drill, a brace with a pointed drill was used for the preparation of nail holes in tough wood. Its point works by crushing material rather than cutting it.159 Also small screw drills160 or an awl can have been used for preparing holes for nails or screws. Early drills could have a spoon shaped iron that resembles that of a gouge and could be used for larger diameters, from 2 cm.161 A twist drill has a spiral shaped shaft that cuts and removes material upwards.162 A centre drill has a flat blade that has a point in the centre, it can have a small knife to pre-cut fibres on one end and a horizontal chisel shaped flat to scrape off material on the other end.163 To countersunk screws a cone shaped drill can have been used.164
145 Ibid. 60.
146 Hayward, Antique, 21.
147 Piena, Beschilderd, 158; Hayward, Antique, 111. 148 Hayward, Antique, 84.
149 Herman den Otter, conversation with author, February 19, 2020. 150 Salaman, Dictionary, 299. 151 Piena, Beschilderd, 158. 152 Ibid. 158. 153 Schindler, “Formspuren,” 435. 154 Ibid. 434. 155 Ibid. 435. 156 Hayward, Antique, 84. 157 Bernard, Étude, 60. 158 Janse, Aaks, 48. 159 Ibid. 70. 160 Schindler, “Formspuren,” 435. 161 Janse, Aaks, 70. 162 Ibid. 55. 163 Ibid. 71. 164 Ibid. 56.
2.3.7 Decorative elements
2.3.7.1 MouldingsMouldings can either be separate elements attached to the carcass, or worked in the solid.165 They can be made by a moulding plane,166 where the blade and the sole have the reverse shape of the intended section and the sole has fences for depth and an equal distance to the side.167 The cutting angle of a moulding plane is usually large, and it acts therefore more like a scraper than a plane to prevent tear outs. Figure 19. Before using the moulding plane the wood is usually prepared by rebate planes or other planes168 or with a circular saw which will make the shape more regular and also prevents tear outs.169 The sole of the plane protrudes beyond and behind the blade so it can only be used on parts clear of obstacles. It cannot start or end halfway a length. A normal moulding plane can only be used on straight or slightly outward curves, but not on inner curves.170 Moulding planes were also expensive equipment, and it is suggested a journeyman cabinet maker or a cabinet maker in the country would not have had a large collection of moulding planes.171
For circumstances where a moulding plane cannot be used or is not available, a scratch stock can be used.172 It does not easily cause tear outs and can be used in both directions.173 The cutter could also be mounted on a bench, and the entire moulding, first roughly prepared to shape, was pulled repeatedly underneath this cutter until the desired shape was reached. This process resulted in more regular shaped mouldings.174 Mouldings can also entirely be made by carving tools, especially when they are of intricate shape.175 Often their ends and inner corners would be tidied with a gouge.176 Some circular shaped mouldings in the 17th century can have be produced by turning.177 An intricate form of a moulding is the wave moulding that was made in a wave-moulding machine that worked similar to the above described process of drawing the moulding underneath of cutters, with a template that guided the cutter to obtain the waves. It was developed in the early 17th century.178 From the mid-19th century, when the wave moulding came back into fashion, new wave moulding machines were developed by larger companies that supplied the market.179
Modern equipment for making mouldings are the spindle moulder or the router.180 The spindle moulder was developed in the second half of the 19th century.181 A treadle operated spindle moulder could in the later part of the 19th century be used in small workshops and allowed intricate moulding work to be executed quickly. In the 19th century also many companies specialised in machine made mouldings, carving, marquetry or turning that could be fitted onto carcasses.182
165 Edwards, Encyclopedia, 143. 166 Ibid. 144.
167 Salaman, Dictionary, 338. 168 Hayward, Antique, 193.
169 Jaap Boonstra, e-mail message to author, March 31, 2020. 170 Hayward, Antique, 191.
171 Ibid. 20-1.
172 Edwards, Encyclopedia, 144. 173 Hayward, Antique, 195.
174 Jutzi and Ringger, “Wellenleiste,” 42. 175 Hayward, Antique, 74.
176 Ibid. 188. 177 Ibid. 196.
178 Jutzi and Ringger, “Wellenleiste,” 36. 179 Ibid. 54.
180 Hayward, Antique, 82. 181 Edwards, Encyclopedia, 129. 182 Ibid. 127.
Figure 19. A moulding being planed with a moulding plane. Photo: Hayward, Antique, 27.
2.3.7.2 Turning on a lathe
Early lathes were powered by a treadle, connected by a rope via a few turns around the work to a flexible pole above. The work rotated towards the operator on the downwards stroke of the treadle, and rotated back by the flexibility of the pole above. The wood could only be worked on the downward rotation.183 The treadle lathe was common in the early Middle Ages.184 To become a continuous movement, the lathe could be operated by an assistant. From the early 16th century,185 or the start of the 17th century186 the lathe was enhanced by a flywheel to ensure a continuous movement, but pole lathe was occasionally still used until into the 20th century.187 Wood for chairs was often turned when still green but pieces in more elaborate constructions, for instance pieces made up of several pieces of wood or with rectangular parts incorporating joints could be made from seasoned wood.188
2.3.7.3 Marquetry and inlay
For the use of inlay, the shapes are cut out of the carcass wood using carving tools, knifes, but also a scratch stock can be used for the inlay of bands.189 The fretsaw that was developed in the mid-16th century allowed for the sawing of intricate shapes in veneers that were used for inlay or for marquetry. Its frame can be up to 50 cm deep, for sawing at a distance from the edge.190 Veneers were often sawn stacked, which produced multiple nearly identical patterns. These patterns could either be inserted in a backing of veneer, that was glued to the carcass that was prepared by cutting out recesses. This was often done with a large knife leaning against the shoulder, worked by a hammer. Another possibility was Boulle work, where all layers, also the ‘background’ of the pattern were used, in different combinations on different pieces. The marquetry or inlay could be glued with the use of hot cauls or sandbags.
2.3.7.4 Carving
For carving gouges, chisels and knifes can be used, with or without assistance of a mallet. Edwards talks about around 1000 variations of carving chisels and gouges.191 Variations can be in the curves, widths, the side of the bevel, the length of the iron,192 the iron being straight or bent in length, etc. But also small planes
183 Hayward, Antique, 181. 184 Edwards, Encyclopedia, 119. 185 Janse, Aaks, 50. 186 Hayward, Antique, 182. 187 Edwards, Encyclopedia, 119. 188 Hayward, Antique, 180. 189 Edwards, Encyclopedia, 190. 190 Ibid. 189. 191 Edwards, Encyclopedia, 43. 192 Janse, Aaks, 72.
and adzes, drills and lathes,193 and rasps and punches are used in carving.194 For flat recesses of the work a router plane can be used.195 The shape can have been prepared using a lathe, for instance legs for tables and chairs that incorporate carving.196 For smoothing a file can be used.197
Edwards discerns several types of carving of which ‘knife chip’ carving is the simplest. A flat surface is decorated using a sharp knife, cutting from two sides to create a short groove with triangular section. ‘High relief’ is the carving of the highest manual and design skill, where the ornament stands out and is undercut. ‘In the round’ is the term for freestanding elements, such as table legs or figures. Originally cut from a single piece of wood, from the early 16th century blocks with different grain direction were joined to ease the process.198
Since the 18th century processes have been devised for imitation of carving.199 Carving machines can be a combination of a lathe, drill and pantograph intended mostly to perform the first stages of carving. The refinement was executed with hand carving tools. Carving machines became important from the mid-19th century but most carving in the 19th century was reportedly still done by hand. From the 1990’s ANC routing machines took over the rough cutting. Still the refinement is done by hand.200
2.3.8 Conclusion
Many tools that are used in woodworking were around in the entire period from the 17th to the 20th century, and are still in slightly modified version used today although to a lesser extent. The largest changes in woodworking were made by the gradual introduction of machines in the 19th century. The traces of the machines are often radically different from the traces of their counterparts in hand tools. A surface might have been worked subsequently with different tools or actions, which might have eradicated the traces of earlier actions.
Now the origin, nature and appearance of toolmarks and the history of woodworking techniques have been discussed. In the next chapter I will explore techniques that can be used in the examination and documentation of toolmarks.
193 Arnold Truyen, telephone conversation with author, June 8, 2020. 194 Edwards, Encyclopedia, 43. 195 Ibid. 43. 196 Hayward, Antique, 75. 197 Edwards, Encyclopedia, 43. 198 Ibid. 43-4.] 199 Ibid. 44-5. 200 Ibid. 45-6.
