The thought of priming has become a distant thought for most painters today. With the broad availability of pre-primed, ready to use, and generally economical supports, it is understandable why this part of painting has fallen by the wayside. Since its advent in the 1950s, acrylic gesso has slowly become the choice primer of acrylic and oil painters. Although it may seem like simple white paint, acrylic gesso is a truly modern material that has solved centuries of technical issues faced by fraught painters. Today acrylic gesso is widely available on nearly every pre-primed support. It is success however is not without caveats. Today at Tri-Art we continue to receive reports of paintings failing due to poor quality priming layers. Today’s article explores the history of ground layers and how artists can select and prepare priming layers to ensure their work stand the test of time.
FOUNDATIONAL: A PRIMER ON GROUND LAYERS
A ground, primer, or preparatory layer is the initial surface laid down by the artists upon their support. It can consist of multiple layers of the same or different materials, built up to achieve a desired effect. When it comes to colour, white grounds have been widely exploited because of their optical effect - when applied thickly enough, they reflect light, giving vibrancy to the colours painted on top of them.[1] This effect was masterfully exploited in the 19th century by the Pre-Raphaelite Brotherhood of painters. These painters sought the brightest pure white ground to reflect light through their painstaking application of glazed oil colour. Additionally, the white ground played a critical role in not only creating their works, but also preserving them. As paintings age, ground layers generally remain white while canvas darkens with age. White grounds therefore are responsible for retaining the brilliancy of colour in painting over time.[2]
Beyond their aesthetic and optical properties, it is important to note that grounds are not just initial layers of paint, but often unique materials that provide important functionality to paintings. Primers, gessoes, and grounds are used in place of paint for their ability to modify the tooth, absorbency, and texture of a support. They provide a uniform layer that will accept the paint with consistency, often preventing its sinking into absorbent supports like wood or canvas and aiding its wetting onto slippery supports like plastic and aluminum. When it comes to oil painting on canvas, grounds serve the critical function of creating a barrier between the acidic oil and canvas. If allowed to come into contact, the acids in oil accelerate the deterioration of canvas, turning it dark, brittle, and fragile.[3]
It has long been understood that the quality of a ground layer will determine both the aesthetic success and long-term survival of a painting. Throughout time artists have readily adapted their materials to achieve surface texture, absorbency, and colour, but have also been keenly aware of the risks of discoloration, flaking and cracking. It’s hard to understate the vast quantity of artists’ treatises and manuals that argue the pitfalls and virtues of using one priming over another. For instance, in the 17th century painters widely utilized a dark reddish-brown ground. For painters like Caravaggio, it gave immediacy to painting by providing a mid-tone that could be used in the final composition. However, by the 18th century it was understood that oil paint gained considerable translucency with age; paintings with dark grounds were seen to be swamped by their red-brown grounds that overtook the tonal balance of the composition with time. Grounds shifted generally to light gray or white with an aim to avoid this colour change. [4]
Today, most viewers would probably deem these changes as acceptable and understand them as part of the natural aging of a painting. Beyond colour changes though, most historical paintings, and even many 20th century modern paintings, have needed some amount of intervention to stabilize cracked, flaking paint. This is nearly always the fault of sizing and ground layers,[5] and makes clear the point – priming is critical to the success and survival of your work.
HIDING IN PLAIN SIGHT: TRADITIONAL GESSOES
Understanding the priming materials of the past and the technical problems that artists faced while using them offers us the clearest understanding of how and why to use modern materials. Today most artist use acrylic ‘gesso’. Gesso is the traditional term for priming applied to Italian panel paintings. The mixture was usually comprised of animal hide glue and white gypsum. It was coopted in the 1950s for acrylic priming, despite having little in common other than its purpose as a ground layer.[6] Many other historical formulations can be found across space and time: several choices of white pigments, bound in flour, animal glue, or drying oil with other additions to modify absorption, flexibility, and adhesion. Glue-based grounds remained a popular mainstay of easel painting since its advent because they offered critical properties for oil painting, mainly absorbency and colour permanence. By removing excess oil from the paint layers above, painters believed that water-based glue grounds could keep a painting looking as fresh as possible for as long as possible, as excess oil darkens over time. Additionally, glue-based grounds themselves did not discolour greatly over time.[7]
Historical treatises on these grounds are extensive and nebulous. What emerges as a clear trend, however, is the technical struggle that artists faced when preparing supports for painting. Glue grounds presented a high risk of flaking, especially if applied too thickly. They were also inflexible, and therefore had a high tendency to crack when rolled for transport.[8] When it comes to the long-term consequences of using a glue ground, these layers are often responsible for the cracking and flaking loss of paint layers. Animal glue grounds tend to be brittle, cracking in response to physical forces or stresses caused by changing humidity over the year. Like a bridge that expands and contracts slightly in the summer and winter, the many component parts and layers of a painting experiences similar dimensional changes as temperature and humidity fluctuates. The hygroscopic animal glue of a traditional glue ground is particularly reactive to these fluctuations in humidity, expanding or contracting enough to place significant shear stress on the bond between paint and ground. Oil paint, with little adhesive strength to begin with, has even less affinity to these water-based glue layers, and so under this stress is liable to flake off the ground under these conditions. At extremely high humidity the effects can be particularly devastating to works on animal glue grounds as animal glue simply reaches a point that it loses all adhesive strength and becomes swollen with moisture.[9] Many historical works are now preserved in carefully climate-controlled settings like museums and galleries to prevent this process from further occurring.
The absorbency of these ground layers appeared to be a double-edged sword. In an era before fast drying paints, an absorbent glue ground offered a means to expedite painting. By absorbing oil from the first layer of colour, it offered the means to rapidly lay down an initial sketch before moving onto more substantial paint layers. However, historical sources also site the challenges of dealing with the resulting tonal shifts and their paint quickly becoming stiff and unworkable upon the canvas. From the 16th century onward an initial glue ground could often be modified with an additional ground layer of oil or glue to reduce its absorbency and potentially add a wash of colour. To find a better balance between absorbency and flexibility, more flexible oil paint, or emulsions of oil and glue were also utilized on their own as ground layers.[10] Oil grounds were also less susceptible to changes in humidity but had their own caveats. Oil and emulsion grounds show more discolouration over the short-term than glue and eventually become inflexible as they age. They also did not have the ability to pull a canvas taught as they dried, one of the hallmarks of animal glues and grounds. Centuries old oil priming layers undergo fascinating chemical changes that render them increasingly transparent. This can result in the appearance of wood grain in panel paintings, dark streaks, or the general darkening of paintings as the reflective ground is lost, particularly if a darker ground layer has been applied beneath the white layer. The chemical changes of the oil grounds can also result in a loss of adhesion, leading to flaking.[11]
We can start to put together a picture of why traditional grounds are so problematic in their own way. With all the issues they had to overcome, we can understand why accounts of artists, colourmen, professional primers, restorers and the likes detailed the laboured effort it was to prevent paintings from falling apart.
PLASTIC MAKES PERFECT: MODERN ‘GESSO’
The solutions attempted by artists in the past to solve their technical problems were quite nearly endless: flour paste grounds, additions of shellac, dusting dry pigments onto a wet ground, or even painting into a wet ground. By the 20th century new solution became available with advancements in chemistry and post-World War industrialization.
In the mid 1950s, acrylic gessoes were developed by Permanent Pigments under the brand Liquitex.[12] Modern acrylic gesso has little in common with historical gesso, instead this modern ground utilizes a mixture of acrylic dispersion, thickeners, white pigments (typically titanium dioxide, also an invention of the 20th century), and other additives like calcium carbonate (chalk) to increase absorbency and give tooth the final surface.
Acrylic gesso is truly more stable than any other priming to come before it. Unlike glue, oil, or natural resins that become brittle and fragile over time, acrylic remains flexible. Because of this it is not liable to ground cracking or flaking.[13] Additionally this chemical stability ensures that it does not discolor and suggests it should retain its opacity over time. Perhaps above all, for most artist today, it is acrylic’s ease of use where it truly shines. Whereas glue and oil grounds needed to be carefully and thinly applied to avoid flaking, acrylic gesso can be applied very thinly or thickly, while retaining flexibility and good adhesion to the support. Acrylic grounds can be modified with more filler like calcium carbonate to add tooth and absorbency, coloured with acrylic paint, or mixed with mediums like modeling paste to give it heavy texture.
Acrylic gesso ultimately fulfilled a technological gap in the world of artists’ materials. Major manufactures began phasing out oil primed grounds in the 1970s,[14] with acrylic now certainly the most popular choice. There is hardly any downside to selecting an acrylic ground to work with, but as with all art materials, quality does play a part.
Cheaper grades of acrylic or vinyl, often found in economical house paints, may contain unstable polymers that cause the paint film to become brittle and yellow over time – these should be avoided, particularly when working on flexible supports like canvas where cracking is more likely.[15] Particularly primer and matte formulations, containing a great deal of filler pigment, will ultimately fail at much lower tensile strengths, likely resulting in cracked turn over edges, and potentially cracking across the picture plane.[16]
When using acrylic gesso, it is also not necessary to size a canvas or support, but it is highly advisable. Users report a phenomenon coined Support Induced Discoloration (SID), the migration of water-soluble components from canvases, panels or others supports into acrylic gesso as it dries.[17] Applying a dilute layer of acrylic medium to your support before priming will seal the surface against any discoloration and greatly help tighten a canvas.
THE PITFALLS OF PRE-PRIMED SUPPORTS
Today many artists will be tempted to reach for the most economical choice of supports, often canvas boards or pre-stretched canvases that come pre-primed in multipacks. These may cost little upfront, but do they pay off in the long run?
The notion of buying pre-primed canvas is quite old. In fact, by the 17th century most priming was undertaken by professionals outside the artist’s studio across Europe. By the 19th century pre-primed canvases were standard issues – white grounds were available in a range of materials and canvases in a range of sizes.[18] Concerns of quality in these products was already quite apparent by the mid 18th century with reports of manufacturers cutting corners to make profits and faulty workmanship leading to a less than desirable product. Poor quality canvases primed with oil grounds were said to come still wet, but also rancid, smelling terrible. An overuse of oil driers in these canvases was said to further cause the white grounds to become yellow, gritty and brittle.[19] To ensure the quality of their canvases’ artists like Turner, Renoir and Monet instead all prepared their own supports.[20]
Today, Tri-Art has found that commercially pre-applied acrylic gesso supports can also be of unacceptably low quality.[21] Economical pre-primed supports may be tempting options, but they also may lack exhibit a dullness in color, a high degree of brittleness, a tendency to crumble, a resistance to wetting, and a lack of adhesion between canvas, ground, and paint layers. These issues can likely be explained by a lack of high-quality acrylic binder and a lack of titanium white pigment. In excess, extender pigments used in place of titanium white yield a greyish-white coloured primer.[22]
A lack of acrylic binder can likely explain issues with crumbling and adhesion. This lack of acrylic binder is also often betrayed by a lack of water resistance.[23] This makes these supports problematic from the outset, but also later as fingerprints and dust are not easily cleaned from these fragile surfaces.[24] In lieu of quality acrylic, particularly inexpensive pre-primed supports may utilize other less expensive resins that are brittle, yellowing, and even water soluble. Vinyl emulsions containing unstable polymers like PVC are one such cause for concern. These brittle resins require considerable amounts of plasticizer, comprising up to 40% of their weight. Unfortunately, the exudation of this plasticizer is also common from these plastics.[25] Today phthalates and other plasticizers remain critical in PVC paint formulations.[26] These primers make a poor choice for artists, as exuding plasticizers can interfere with the adhesion of paint layers, create surface haze, and return the PVC to its naturally brittle state.
A quick litmus test for quality gesso is simply to try wiping the surface with a wet sponge or rag. If the gesso is of poor quality, white particles will readily lift away from the surface.[27] This has the added benefit of removing any water-soluble sizing layer that has been applied by the manufacturer to prevent these canvases from sticking together during transit. Most importantly though wiping your supports down will remove excess surfactant from the surface. All acrylics are made with surfactants that are generally in excess once the paint or gesso is dry. These surfactants can migrate to the surface causing issues with adhesion, gloss, and clarity of applied paint films. Particularly when left to sit in dark storage (like in warehouses or store backrooms), these surfactants will migrate to the surface. The good news is they can be readily and safely removed with water.[28]
Here is a comparison between a very inexpensive pre-primed canvas purchased at a discount store and Tri-Art’s artists’ quality pre-primed eco-canvas. The discount canvas is unusually stiff and inelastic – simply folding the canvas over itself fractures the priming and creates a sharply held fold line. Tri Art’s 100% acrylic gesso retains the flexibility of canvas – it can be aggressively folded and still barely holds a crease, let alone cracking. It is also tough, with aggressive washing producing little change when tested. In comparison the discount canvas priming was water soluble, producing a milky run off when rubbed with a wet cloth. After washing holes can be seen in the canvas.
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When it comes to the possible issues of less ideal quality in pre-primed supports, it is always better to prime your own if possible or buy from reputable manufacturer. If your pre-primed canvas is of dubious quality the stability of your work will always be tenuous and will not be solved with more coats of paint or primer. Here at Tri-Art, we prime all our supports with our highest quality artists' gesso without exception. We encourage our artists to primer their own supports and explore the many potential surfaces possible with acrylic gesso.
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OIL AND WATER: MIXED MEDIA APPLICATIONS
Some oil painters have a deep connection to the material history of their medium and an even deeper distrust of the modern. As explored before historical options for primings consisting of animal glues, drying oils, and natural resins all have limitations and issues when it comes to application, use and aging. Acrylic solved these issues, but is it compatible with oil paint?
First, animal glue grounds are simply not available commercially and must be prepared by oneself if you wish to explore using them. When considering their sensitivity to changes in humidity and their tendency to crack and flake these grounds are no longer advisable for practicing artists. Anyone who has worked with traditional animal glues or gesso will know that the smell alone is enough to switch to acrylic gesso. Unpleasant to say the least, animal glues are also susceptible to bacterial and mold overgrowth that ruin them. They must also be applied warm, also making them liable to overheating and breakdown (think of when your Jell-O® recipe fails). Furthermore, artists might just feel uncomfortable using animal derived products in their work. Today’s oil painters largely have the choice between alkyd modified oil priming or acrylic gesso.
Unfortunately for the traditionalists, acrylics outperform alkyds on nearly every front. By far acrylic grounds greatest advantage over oil is their adhesion to water-based sizing layers applied to the canvas. Oil and alkyd have little adhesive strength, particularly to water-based materials and may delaminate over time.[29] These sizing layers are necessary when applying oil and alkyd grounds to isolate the support from the acidic content of the oil. Their lack of adhesion immediately poses a long-term risk to the security of oil and alkyd grounds. Despite this, oils and alkyds still adhere very well to acrylic gesso, likely due to its absorbency. This research comes not just from the short term, or controlled lab experiments. An extensive survey of the Tate’s collection found half of oil paintings post 1963 were painted on acrylic grounds. None of these works were found to exhibit adhesion issues.[30]
Acrylics also outperform alkyds when it comes to flexibility. Even when aged, acrylic emulsion grounds should survive some degree of bending and straining. Alkyd grounds on the other hand are not very flexible, making them vulnerable to cracking on the folder over edge and across the surface. [31] This effect is exacerbated in the cold Canadian climate, as alkyd primers show little plasticity below 30-40 °C. Acrylic grounds are much more suited to the cold, remaining somewhat flexible to as cold as 0 °C. [32] Acrylics are in fact so flexible they can impart some of this quality to oil and alkyd layers painted on them. By increasing the flexibility of oil paintings, acrylic gesso can prevent cracking over time.[33]
Lastly acrylics will certainly outperform alkyd grounds when it comes to colour retention. Alkyds and oils have a natural tendency to slightly yellow, even in the short-term. White acrylic gesso will retain its white colour for much longer, functioning as a brilliant optical reflector for light through your painting.
As with any choice of material, there are caveats to painting in oil over acrylic. When it comes to using solvents, mediums and varnishes, acrylic grounds must also be considered. Acrylic is often soluble in solvents like xylenes and turpentine. While most artists no longer use these in their painting practice, these are still commonly found in acrylic and dammar varnishes formulated for oil paintings. A better alternative for paintings on acrylic gesso would be varnishes and mediums containing only odourless mineral spirits, especially if you have left areas of the ground exposed. Make sure to always test your varnish in discrete areas before applying it to whole surface.
Additionally, with oil on acrylic, support reuse is particularly limited. Some online tutorials suggest that oils can be scraped down and sanded before reapplying more acrylic gesso. This may well work in the short-term, but the adhesion of the acrylic to oily layers (including acrylic gesso that has absorbed oil from the applied paint layers) will always be tenuous. When it comes to reusing supports, it is best to either remove all paint and ground layers, by sanding back down to the wood of a panel for instance, or just using these supports for process work that is not intended to be finished or permanent work.
PRIMING: PRACTICAL TIPS FOR ARTISTS
- The current research – both from collections surveys of early acrylic use, and lab work – shows that acrylic grounds are a very stable, sound choice for any paint medium. It is likely the ideal choice for your work.
- Whenever possible apply your own sizing and/or acrylic priming layers to ensure that you are using a quality product, like Tri-Art artists’ gesso. Always refer to product labels. Look for products labeled as 100% acrylic polymer emulsion. Do not use wall primer which is meant for a rigid support and not formulated to be archival – its lack of flexibility can ultimately cause cracking and flaking from a flexible support like canvas.
- When in doubt about a gesso, or if trying your own modified acrylic ground formula, you can easily test your gesso by pouring out a small puddle on a piece of paper or scrap of canvas – once dry, try flexing it. If it cracks. Do not use it on a flexible support like canvas.[34]
- Sizing and priming are much more economical than paint – if economy is important to you, then ensure that your support is well prepared and that no pigment goes to waste
- It is always best to size your support to prevent discolouration from migrating into your ground and paint layers – this is particularly true for wood panels, canvases and any atypical supports that may have water soluble colourants. Use a high-quality acrylic product to ensure the best results.
- All acrylic paint contains surfactants, generally that are in excess once the paint is dry. To ensure an excellent bond between paint and priming, use a damp sponge or cloth to wash away any excess surfactant, particularly from all pre-primed supports. This will also wash away any sizing left by the manufacturer. Be careful not to use so much water as to warp wood or canvas panels.
- When using atypical supports always test the adhesion of your intended size, ground, or paint layers. Adhesion may take up to two weeks to develop as the acrylic fully dries.
- Due to its porous nature, acrylic gesso is more fragile and difficult to clean than acrylic paint,[35] if you plan to keep a significant part of the ground exposed in your composition consider laying down a thin layer of acrylic paint across the whole support before painting your design.
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BIBLIOGRAPHY
Gottsegen, M D, ‘Sizes and Grounds’, in The Painter’s Handbook: A Complete Reference (Watson-Guptill Publications, 2006), pp. 51–72 <https://books.google.ca/books?id=o23u0SuRLxsC>
Hackney, Stephen, On Canvas : Preserving the Structure of Paintings (Los Angeles: The Getty Conservation Institute, 2020)
Hagan, Eric, Maria Charalambides, Thomas J S Learner, Alison Murray, and Christina Young, ‘Factors Affecting the Mechanical Properties of Modern Paints’, in Modern Paints Uncovered: Proceedings from the Modern Paints Uncovered Symposium, ed. by Thomas J S Learner, Patricia Smithen, Jay W Krueger, and Michael R Schilling (Los Angeles: Getty Conservation Institute, Los Angeles, United States, 2007), p. pp.227-235, 8 figs., 4 tables, refs.
Jayakrishnan, A, M C Sunny, and Mini N Rajan, ‘Photocrosslinking of Azidated Poly(Vinyl Chloride) Coated onto Plasticized PVC Surface: Route to Containing Plasticizer Migration’, Journal of Applied Polymer Science, 56.10 (1995), 1187–95 <https://doi.org/https://doi.org/10.1002/app.1995.070561001>
Kelly, D G, ‘The Effect of Water Resistance on the Durability of Waterborne Coatings’, Paint & Coatings Industry, 19 (2003), 38
Noble, Petria, Annelies van Loon, and Jaap J Boon, ‘Selective Darkening of Ground and Paint Layers Associated with the Wood Structure in Seventeenth-Century Panel Paintings’, in Preparation for Painting: The Artist’s Choice and Its Consequences, ed. by Joyce H Townsend, Tiarna Doherty, Gunnar Heydenreich, and Jacqueline Ridge (London: Archetype Publications Ltd., London, United Kingdom, 2008), p. pp.68-78, 7 figs. (6 color), 1 table, 12 notes, re
Ormsby, Bronwyn A, Eric Hagan, Patricia Smithen, and Thomas J S Learner, ‘Comparing Contemporary Titanium White-Based Acrylic Emulsion Grounds and Paints: Characterisation, Properties and Conservation’, in Preparation for Painting: The Artist’s Choice and Its Consequences, ed. by Joyce H Townsend, Tiarna Doherty, Gunnar Heydenreich, and Jacqueline Ridge (London: Archetype Publications Ltd., London, United Kingdom, 2008), p. pp.163-171, 5 figs., 5 tables, 5 notes, refs.
Pearce, Richard, ‘Dispersing Pigment/Filler Concentrates in Plasticizer Dispersions’, Plastics, Additives and Compounding, 6.4 (2004), 36–39 <https://doi.org/https://doi.org/10.1016/S1464-391X(04)00238-7>
‘Sizes and Grounds’, Gamblin Artists’ Colors <https://gamblincolors.com/oil-painting/sizes-and-grounds/> [accessed 26 April 2021]
Stols-Witlox, Maartje, A Perfect Ground : Preparatory Layers for Oil Paintings, 1550-1900 (London: Archetype Publications, 2017)
Stols, Maartje, Bronwyn Ormsby, and Mark Gottsegen, ‘Grounds, 1400-1900 - Including: Grounds in the Twentieth Century and Beyond’, in The Conservation of Easel Paintings, ed. by Joyce Hill Stoner and Rebecca Rushfield, Second (Abingdon: Routledge, 2021), pp. 163–91
Tauchid, Rheni, Acrylic Painting Mediums & Methods : A Contemporary Guide to Materials, Techniques, and Applications , Acrylic Painting Mediums and Methods, First edit (New York, New York: Monacelli Studio, 2018)
———, New Acrylics Essential Sourcebook : Materials, Techniques, and Contemporary Applications for Today’s Artist (New York: Watson-Guptill Publications, 2009)
‘Why We Recommend Unprimed Canvas’, Art Noise <https://shop.artnoise.ca/blogs/art-noise-handbook/why-we-recommend-unprimed-canvas> [accessed 26 April 2021]
Young, Christina, ‘Interfacial Interactions of Modern Paint Layers’, in Modern Paints Uncovered: Proceedings from the Modern Paints Uncovered Symposium, ed. by Thomas J S Learner, Patricia Smithen, Jay W Krueger, and Michael R Schilling (Los Angeles: Getty Conservation Institute, Los Angeles, United States, 2007), p. pp.247-256, 7 figs. (5 color), 3 tables, refs.5
Young, Christina, and Eric Hagan, ‘Cold Temperature Effects of Modern Paints Used for Priming Flexible Supports’, in Preparation for Painting: The Artist’s Choice and Its Consequences, ed. by Joyce H Townsend, Tiarna Doherty, Gunnar Heydenreich, and Jacqueline Ridge (London: Archetype Publications Ltd., London, United Kingdom, 2008), p. pp.172-179, 7 color figs., 2 tables, 4 notes, refs
FOOTNOTES
[1] Stephen Hackney, On Canvas : Preserving the Structure of Paintings (Los Angeles: The Getty Conservation Institute, 2020).
[2] M D Gottsegen, ‘Sizes and Grounds’, in The Painter’s Handbook: A Complete Reference (Watson-Guptill Publications, 2006), pp. 51–72 <https://books.google.ca/books?id=o23u0SuRLxsC>.
[3] Gottsegen.
[4] Maartje Stols-Witlox, A Perfect Ground : Preparatory Layers for Oil Paintings, 1550-1900 (London: Archetype Publications, 2017).
[5] Hackney.
[6] ‘Sizes and Grounds’, Gamblin Artists’ Colors <https://gamblincolors.com/oil-painting/sizes-and-grounds/> [accessed 26 April 2021].
[7] Stols-Witlox.
[8] Stols-Witlox.
[9] Hackney.
[10] Stols-Witlox.
[11] Petria Noble, Annelies van Loon, and Jaap J Boon, ‘Selective Darkening of Ground and Paint Layers Associated with the Wood Structure in Seventeenth-Century Panel Paintings’, in Preparation for Painting: The Artist’s Choice and Its Consequences, ed. by Joyce H Townsend and others (London: Archetype Publications Ltd., London, United Kingdom, 2008), p. pp.68-78, 7 figs. (6 color), 1 table, 12 notes, re.
[12] Maartje Stols, Bronwyn Ormsby, and Mark Gottsegen, ‘Grounds, 1400-1900 - Including: Grounds in the Twentieth Century and Beyond’, in The Conservation of Easel Paintings, ed. by Joyce Hill Stoner and Rebecca Rushfield, Second (Abingdon: Routledge, 2021), pp. 163–91.
[13] Hackney.
[14] Stols, Ormsby, and Gottsegen.
[15] Hackney.
[16] Eric Hagan and others, ‘Factors Affecting the Mechanical Properties of Modern Paints’, in Modern Paints Uncovered: Proceedings from the Modern Paints Uncovered Symposium, ed. by Thomas J S Learner and others (Los Angeles: Getty Conservation Institute, Los Angeles, United States, 2007), p. pp.227-235, 8 figs., 4 tables, refs.
[17] Gottsegen.
[18] Stols, Ormsby, and Gottsegen.
[19] Stols-Witlox.
[20] Stols, Ormsby, and Gottsegen.
[21] ‘Why We Recommend Unprimed Canvas’, Art Noise <https://shop.artnoise.ca/blogs/art-noise-handbook/why-we-recommend-unprimed-canvas> [accessed 26 April 2021].
[22] Hackney.
[23] D G Kelly, ‘The Effect of Water Resistance on the Durability of Waterborne Coatings’, Paint & Coatings Industry, 19 (2003), 38.
[24] Stols, Ormsby, and Gottsegen.
[25] A Jayakrishnan, M C Sunny, and Mini N Rajan, ‘Photocrosslinking of Azidated Poly(Vinyl Chloride) Coated onto Plasticized PVC Surface: Route to Containing Plasticizer Migration’, Journal of Applied Polymer Science, 56.10 (1995), 1187–95 <https://doi.org/https://doi.org/10.1002/app.1995.070561001>.
[26] Richard Pearce, ‘Dispersing Pigment/Filler Concentrates in Plasticizer Dispersions’, Plastics, Additives and Compounding, 6.4 (2004), 36–39 <https://doi.org/https://doi.org/10.1016/S1464-391X(04)00238-7>.
[27] Rheni Tauchid, New Acrylics Essential Sourcebook : Materials, Techniques, and Contemporary Applications for Today’s Artist (New York: Watson-Guptill Publications, 2009).
[28] Bronwyn A Ormsby and others, ‘Comparing Contemporary Titanium White-Based Acrylic Emulsion Grounds and Paints: Characterisation, Properties and Conservation’, in Preparation for Painting: The Artist’s Choice and Its Consequences, ed. by Joyce H Townsend and others (London: Archetype Publications Ltd., London, United Kingdom, 2008), p. pp.163-171, 5 figs., 5 tables, 5 notes, refs.
[29] Hackney.
[30] Ormsby and others.
[31] Christina Young, ‘Interfacial Interactions of Modern Paint Layers’, in Modern Paints Uncovered: Proceedings from the Modern Paints Uncovered Symposium, ed. by Thomas J S Learner and others (Los Angeles: Getty Conservation Institute, Los Angeles, United States, 2007), p. pp.247-256, 7 figs. (5 color), 3 tables, refs.5.
[32] Christina Young and Eric Hagan, ‘Cold Temperature Effects of Modern Paints Used for Priming Flexible Supports’, in Preparation for Painting: The Artist’s Choice and Its Consequences, ed. by Joyce H Townsend and others (London: Archetype Publications Ltd., London, United Kingdom, 2008), p. pp.172-179, 7 color figs., 2 tables, 4 notes, refs.
[33] Young.
[34] Rheni Tauchid, Acrylic Painting Mediums & Methods : A Contemporary Guide to Materials, Techniques, and Applications , Acrylic Painting Mediums and Methods, First edit (New York, New York: Monacelli Studio, 2018).
[35] Ormsby and others.
