Jacksons Art store in London asked me to compare the range of Cold Wax Mediums that are available for their blog. I compared them the side by side in various situations as well as completing six small paintings, each using one of the six mediums. Along the way, I demonstrate the many ways to make marks and create layers when painting with cold wax medium.

When mixed with solvent, beeswax becomes soft enough to paint with, without the need for the application of heat. By adding a resin for strength you create a cold wax painting medium. Cold wax medium has such distinct characteristics when mixed with oil paint that this type of painting has its own name: Cold Wax Painting. The paint and medium mixture is often applied by spreading with a knife or scraper. Cold wax medium thickens oil paint so it allows for carved-in marks and creating this texture in the surface is an important part of the painting process for many cold wax painters. Collage can also be incorporated for mixed-media painting. As soon as the solvent evaporates the mixture begins to harden or dry, this speeded up drying allows fast painting in layers.

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I create paintings and monoprints, both media inform the other and are often combined in a single piece. I begin each painting by building texture and colours with acrylics before adding many layers of oil, pigments and cold wax medium. Through a process of scraping and re-working, I achieve a highly textural surface and reveal the underlying colours. After many layers, I tame the chaos by redefining the design with strong shapes, lines and structure.

I have been using Cold Wax Medium (CWM) with oil paint in my work for a while and I really enjoy how it allows me to make marks, build texture and scrape back; concealing and revealing. It can also be used as a ‘glue’ to attach collage elements, and as a finishing wax as an alternative to varnish on acrylic, oil and watercolour paintings and photographs. As a printmaker I love how CWM can be used with many of my printmaking tools: rollers, spreaders and engraving tools; even tools from the kitchen find their way into my studio: basting brushes, skewers and whisks to name a few. The medium changes the consistency of the oil paint by making it thicker, the dry paint has a nearly matt sheen, and the drying time is accelerated. As an added bonus the rules of “fat over lean” no longer apply as the oil is suspended in the wax medium.

The two brands of Cold Wax Medium I have used before are Gamblin and Zest-it, and I now make my own recipe for my own work and my workshops, that I call SalCera (a combination of Sally and Cera, which is Spanish for wax). But I am often asked by participants on my workshops about the differences and similarities between the brands available, in particular their texture, drying times, sheen, flexibility and smell. So when Jackson’s asked me to do a product comparison I was more than happy to do so. Whilst I am a self-confessed materials geek I’m not a scientist, so the results of my “experiments” should be taken in the spirit they are intended – to share knowledge and experience, but not used as definitive answers.

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What is Cold Wax Medium?

CWM is a wax-based medium that you mix with oil paint. Most consist of beeswax, a resin and a solvent. Most brands use either damar or alkyd as resins. Both resins help to cure the beeswax, make it durable and less sensitive to heat. Without the addition of a resin, the wax would remain fairly soft. It has been a popular medium in the USA for decades but is relatively new in Europe. It is not the same as encaustic painting which involves heating wax until it melts, adding resin and pigment and applying it to a surface whilst in its molten state. By contrast, CWM has a short, buttery consistency; it also cannot be heated or mixed with water-based media. Whilst its soft edges and rich texture appeal to landscape and abstract painters, any genre of painting is possible as illustrated in the excellent book by Rebecca Crowell and Jerry Mclaughlin Cold Wax Medium: Techniques, Concepts & Conversations.

(Click to enlarge the image)

The six products I tested are made by Gamblin, Dorland’s, Zest-it, Michael Harding, Wallace Seymour, and my own recipe SalCera. In addition, I tested a few solvents, mediums and additives to see how the wax mediums can be extended and altered. Links to all products are below. Not all of the information on all of the products that I tested is available but most companies provide information on their websites on what their products contain and how to use them, as well as safety data sheets.

This chart shows the ingredients used in each product and the manufacturer’s recommended percentage of the medium when mixed with oil paint.

Brand	Wax	Solvent	Resin	Oil	% of Medium
Gamblin	Beeswax	Gamsol (OMS)	Galkyd		33-50%*
Dorland’s	Beeswax, Paraffin, Microcrystalline	Odourless Mineral Spirits	Dammar		33-50%*
Zest-it	Beeswax	A citrus-scented turpenoid**	Dammar	Linseed	50%*
SalCera	Beeswax	Gamsol (OMS)	Galkyd		50%*
Michael Harding	Beeswax	Distilled turpentine	Dammar	Linseed	20%
Wallace Seymour	Beeswax	Co-Co Bello Diluent	Dammar	Linseed	20%

*A higher percentage can be used on hard surfaces.
**actual ingredient information unavailable

As with most products of this nature some contain ingredients that can cause irritation. I would always recommend using them in a well-ventilated studio, wearing gloves to prevent skin absorption and taking note of any symptoms. If you do have a reaction it is more than likely to be a solvent, but as Julie Caves points out in her excellent Jackson’s blog post on solvents it is very much an individual response, what suits one person may not suit another.
The oil paints I used are from Jackson’s Professional range and Williamsburg but any good quality oil paint is fine to use with cold wax medium. I would recommend using those that are stiffer. A loose oil paint with lots of oil will affect both the viscosity of your medium and the drying times. I used the same colours on each panel for consistency as different colours have their own inherent drying times. Pigments like umbers dry at rates much faster than modern organic pigments. An excellent chart on oil paint drying times and opacity can be downloaded here.

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Strength of Solvent Odour in Each Medium

The first thing one notices when opening each jar or tin is the smell. How does one describe a smell? What smells strongly for one person does not for another and vice versa. For this test I lined the jars up in front of my husband as I had prior knowledge of the ingredients that might sway my opinion. I asked him to give each jar a rating from 1-10, 1 being no smell and 10 being strong smelling. These are the results of our smell test and his descriptions:
1 Dorlands “a delicate wax smell like lemony polish”
2 Gamblin “a soft smell, similar to putty”
2 SalCera “smells like the putty one”
3 Wallace Seymour “reminds me of my grandmother’s furniture polish”
5 Zest-It “a chemical orange smell like kid’s sweets”
9 Michael Harding “smells strongly of turpentine”

The differences in smell lie mainly in the amount and type of solvents used. Dorlands, Gamblin and SalCera are mixed with good quality odourless mineral spirits, which along with the Zest-it citrus-scented turpenoid are reportedly safer for both the artist and the environment than turpentine. The Wallace Seymour appears to be mostly beeswax suspended in linseed oil and does not smell of solvent, however, according to the company the wax is dissolved in a “natural plant-based diluent” called Co-Co Bello. The Michael Harding clearly states their wax medium contains distilled turpentine, which is a much stronger smelling solvent than either odourless mineral spirits or Zest-it dilutent.

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Textures of the Cold Wax Mediums

The next aspect I explored was their texture. I was surprised by how different they all were. I filmed a series of short videos to enable you to see the differences in texture and viscosity. Whilst they vary in colour I found that once mixed with paint and dry, the colour of the wax is not evident. The thickest is the Zest–It, it is slightly ‘gritty’, so thick you can cut it with your palette knife. Gamblin and SalCera were both similar to the Zest-It but slightly smoother and whiter. The Wallace Seymour is yellow, thick and chunky, it clearly contains a lot of linseed oil so has a very rich consistency. The Dorlands is white, smooth and creamy, probably due to its slightly higher ratio of solvent, and the use of both paraffin and microcrystelline waxes, which are inherently smooth and clear. The thinnest was Michael Harding, it was even thinner than the oil paint I used, and when worked with the knife became even looser.

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Adding Solvent, Oil or Powders

There are times when you may want to adjust the viscosity of the medium to make them flow for brush work. Used sparingly Linseed Stand Oil can be added but this will slow drying time. If mixed with an equal amount of solvent you can create a traditional slow-drying, low-viscosity painting medium to add to your oil and CWM mix. However, if you want to maintain the drying time then there are other mediums available. Zest-it Clear Painting Medium which is a blend of their Zest-it solvent and linseed oil, and Chelsea Classical Studio’s Clarified Lean Medium that is a mixture of cold-pressed linseed oil and lavender spike oil essence will both decrease drying time and thin the paint.

Both Zest-It and Gamblin make additional gel-like products that can be added to cold wax mediums. I had read that the two resins used in wax mediums, damar and alkyd, are not compatible so it is worth keeping to one brand. With that in mind, I experimented thinning the damar resin-based mediums: Dorland’s, Zest-it and Michael Harding with Zest-it LiquiBlend Wax. I thinned the alkyd-based mediums (Gamblin and SalCera) with Gamblin Galkyd Gel. Both of these products reduced the viscosity of the mediums to allow for smooth brushwork. As the Michael Harding is quite thin to start with, adding the Zest-it LiquiBlend created a very fluid paint. Conversely, it is possible to thicken the mediums by adding absorbent powders such as marble dust and limestone dust, but this will affect the opacity and tint the colour. Zest-It produce a range of additives including limestone dust, which made the Michael Harding much thicker and tinted the medium a soft brown, this is less evident when mixed with paint but a factor worth considering if you like using transparent layers.

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Comparing the Cold Wax Mediums

Having explored the ingredients and viscosity of each medium I set about some trials. Three questions that I am always being asked are about the ratios of medium to paint, drying times and the flexibility of dried paint. For some artists being able to roll a painting for shipping or transportation is an important factor. I devised a test that would answer all of these questions by creating a chart on canvas that once fully dry I could roll and crease to see which medium stands up to rough handling! On my test chart I tested them all to a range of ratios. Finally, I added Galkyd to each of the 50:50 mixes to see how flexible it would make the paint.

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Proportions

As wax is essentially a brittle substance it is recommended that rigid supports are used. However, that very much depends on the ratios of oil to CWM and whether additional resins such as alkyd mediums are used to add flexibility. Gamblin and Dorland’s recommend using a ratio of 1:2 oil paint to medium, but if using a rigid surface or adding additional resins the ratio of wax to paint can go higher and most artists use a 1:1 mix as a baseline. Zest-it advises not more than 50% wax should be used. Michael Harding and Wallace Seymour advise not more than 20% wax. In my own work, I tend to use a 50% wax mix, but I add additional alkyd mediums to increase flexibility if I’m working on paper or canvas instead of a rigid surface.

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Drying time

On my test chart the neat Gamblin, Zest-it, Dorland’s and SalCera were all touch dry within 24hrs, the Michael Harding took 72 hours and the Wallace Seymour is still wet at the time of writing three weeks later. However, when mixed with paint to their recommended ratio of 20% the Michael Harding was touch dry in two days and the Wallace Seymour touch dry after four days. There was surprisingly little difference in drying times between the ratios for Gamblin, Dorland’s, Zest it and SalCera. As it was the only one of the four to contain Linseed oil the Zest-it took a slightly longer time to dry. Drying times vary enormously depending on the thickness of paint, the pigment used and the ambient temperature, so any figures are only a guide.

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Layering

Finally, I felt I could start painting! I used a 20cm square plywood panel to make a painting with each brand of CWM. The first layer on all the panels was Cerulean Blue using a silicone spreader. After the initial process of laying down one colour, it soon became apparent that this was going to be a layering test for those mediums which are touch dry within a reasonable time, enabling a second coat to be applied without disturbing the first.

The weather was warm and sunny and as expected the Gamblin, Dorland’s, Zest-it and SalCera were dry enough in a few hours to add a second layer using a roller. This was an opaque layer of Titanium White with Prussian Blue. It was interesting to see how each medium rolled on, clearly, the stiff Zest-it allowed for a greater degree of texture.

Once applied, I used both a wooden kebab stick and the edge of my silicone scraper to score into the surface revealing the Cerulean blue underneath.

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Wiping with Solvent

A favourite Cold Wax technique is using solvents to remove a layer of paint.

I used Gamsol with both a needle applicator and a brush to each of the panels. After a few minutes, I used my silicone scraper to wipe away, revealing the layer underneath.

In the Gamsol wipe test the “cleanest” wipe was achieved with the Dorland’s medium (shown on the left) as it went on much smoother than the others. The action of dragging down over the thick Zest-it (shown in the centre) resulted in a blurred edge. I left the Michael Harding panel to get touch dry before adding the Titanium White and Prussian Blue layer, leaving it for another two days before doing the wipe which left a smudgy, atmospheric result (shown on the right).

In addition to noting how each wax reacted differently to solvent, I was interested to see how the different solvents would perform for ‘wiping’. I painted a spare panel with a layer of a mixture of opaque paint and cold wax medium and once touch-dry tested the following by dribbling down a teaspoonful of each, waiting a few minutes before wiping downwards with my silicone scraper. In order of strength: the English Distilled Turpentine cut into the paint with the most vigour, next was the Zest-it Solvent, and then the Shellsol T and Gamsol which both dissolved an equal amount of paint. I hadn’t used the Chelsea Classical Studio Lean Medium before and presumed that as it smelt so strongly, in a pleasant way, it would behave with ‘strength’ but of course, although it contains a solvent it is an oil medium so it didn’t dissolve the paint at all! Proof that smell is not an indicator of strength, and reading the label always helps!

Solvent strength of dissolving the wax, from strongest to weakest:

• English Distilled Turpentine
• Zest-It Wax Solvent
• ShellSol T Odourless Solvent
• Gamsol Odourless Mineral Spirits
• Chelsea Classical Studio Lean Medium (with spike lavender oil solvent)

Solvent test to remove wax, left to right:
English Distilled Turpentine, Chelsea Classical Lean Medium (notice that it didn’t remove any wax at all), ShellSol T, Zest-It Wax Solvent, Gamsol

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Glazing

As I like to work with both opaque and transparent layers I returned to the six touch-dry panels to lay down a thin glaze of Indian Yellow mixed with CWM once the second layer was touch dry. To the Gamblin and SalCera I added a little Galkyd and Gamsol to increase viscosity, to the Zest-it and Michael Harding I added some Zest-it Clear Painting Medium, and to the Dorland’s I added Chelsea Classical Studio Lean Medium. I used the silicone spreader to apply the glaze. Each glaze behaved differently, the Gamsol/Galkyd glaze spread over evenly, as did the Zest-it but the stronger solvent in the Zest-it it began to “wake up” the opaque layer underneath, muddying the glaze. The most successful glaze was the one diluted with the Chelsea Classical Studio Lean medium. The Dorland’s is smoother to start with, and the Lean is a medium, not just a solvent, so it did not affect the opaque layer, giving me more time to spread the glaze evenly. I could have used Linseed oil to create the glaze but that would have meant a longer drying time before adding the fourth layer.

To provide more texture I used a Princeton silicone brush to some areas.

The fourth layer was one I made with Titanium White tinted with Yellow Ochre.

With one panel I masked off areas with blue masking tape before adding the white layer with a roller.

When applying the tinted white Dorlands with the scraper I noticed that as it was smoother it settled nicely into the texture left by the silicon brush.

With the stiffer mediums, I left texture in the paint with the silicone scraper and kitchen whisk.

Finally, on all panels I removed areas of paint using a pottery loop tool, revealing the layers underneath. This was less successful with the Michael Harding panel, but the results were soft and impressionistic.

Once this white layer had dried I laid on another glaze of Williamsburg Green Gold mixed as before but with this layer, I tried more techniques.

I blotted off areas of glaze with newsprint that had been screwed up and spread out again. I laid it on and using a clean roller to press it into the paint. I sprayed solvent on from a spray bottle wiping away the dissolved areas. Both of these techniques remove the glaze but leave a texture.

What all of these techniques allow is for the artist to explore in ways that are only possible with cold wax medium.

The sixth and final layer that all the panels had in common was a transparent glaze layer of Prussian Blue. For this I cut shapes from copy paper to mask off areas, providing bold shapes to contrast with the textures.

After this layer, while keeping to the palette I was using, I treated each panel individually to finish them. I added more opaque and transparent layers and scored into them with tools. Mixing the Michael Harding with Titanium White and the Zest-It Limestone Dust provided a lovely grey that was touch dry in 24 hours.

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Blending with the Michael Harding and Wallace Seymour mediums

Having finished the panels that dried faster, I returned to the slower-drying Michael Harding and Wallace Seymour mediums. The Michael Harding panel was dry enough to work on after two days, and allowed a greater ratio of wax to paint but it was a much slower process to work with layers, and the texture was too smooth to build impasto. The Wallace Seymour medium could be used with layers as I had with the others, if I had kept to the recommended 20% ratio, but again it would still be a much slower process. These were clearly mediums that had different properties, and consequently different uses to those that I would define as true Cold Wax Mediums. Both would be excellent to use for Alla Prima painting and creating a piece in one session.

With this in mind, I decided to test their blending qualities. I mixed each with paint to a 20:80 ratio, and alongside I did a control test with plain paint. The Michael Harding allowed for a greater degree of blending that the plain paint, it was soft and creamy to work and dried with a matte finish after 48 hours. The Wallace Seymour allowed for more impasto texture but still blended well although it had a longer drying time than the plain paint.

I could alter the viscosity of both by either adding Zest-It LiquiBlend to loosen them or by adding marble or limestone dust to thicken them which would also decrease their drying time. I particularly liked how both dried with a matt finish.

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Cracking test

Finally, it was back to my canvas test panel, how would it cope being rolled and folded? I had left it for four weeks and all the sections were dry, except the Wallace Seymour sections which were mixed with a higher ratio of wax than recommended. The section of Wallace Seymour where I had added Galkyd to a 50/50 mix had dried after a few days indicating that either low wax ratio and/or some resin is required to enable it to dry.

I rolled and folded the canvas and then set about creasing it along each section. I was rough with it!

Interestingly the only sections that showed any sign of splitting were the plain, unmixed sections, except those with linseed oil. Although in theory alkyd resin gives both strength and flexibility to paint layers, whilst dammar would impart its inherent brittleness to paint layers, in my test they were equally flexible. The fact that none of the painted sections cracked, indicating that even a little linseed oil present in the oil paint has a protective quality.

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Will it melt?

The final question I am always asked when I say I use wax medium is “Will it melt?” This summer I drove from Southern Spain to the UK with a number of paintings in my car. The days were warm and the car developed a lovely waxy smell. I was relieved to find when unpacking them that nothing had “shifted” on the journey. However, to fully test this I put a piece of canvas with plain dried paint, and a piece with a 50-50 paint and cold wax medium mix in the sunshine on a sunny day for an afternoon and neither sample went even slightly soft. Of course, I wouldn’t recommend any painting is put in direct sunlight or left in a hot car, but I would argue that paintings made with oil and wax medium are as stable as oil paintings without wax medium.

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The Finished Paintings

Finished painting on panel using Dorland’s cold wax – Sally Hirst

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Finished painting on panel using Zest-it cold wax – Sally Hirst

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Finished painting on panel using Gamblin cold wax – Sally Hirst

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Finished painting on panel using Salcera cold wax – Sally Hirst

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Finished painting on panel using Michael Harding Beeswax Paste – Sally Hirst