Índice / Contents
- 1 Basic materials of encaustic painting
- 2 Waxes
- 3 Resins
- 4 Pigments
- 5 Notes & Multimedia content
Basic materials of encaustic painting
The encaustic paint or medium is very easy to make. To make the encaustic medium you only need 2 materials: beeswax and damar resin. If you want to colour it, you also need powder pigments (or oil tubes). Encaustic paint does not need to be varnished, it does not need neither dryers nor modifiers, it does not require any type of additive since encaustic paint is eternally preserved in solid form and needs nothing but heat to become fluid again. It is a very old pictorial technique that is being rediscovered but about which there is still little information about: what is encaustic?
Encaustic painting techniques are endless, but they all have a common basis in which 3 materials are used: beeswax, damar resin and pigments. First, you will need pure beeswax, this seems a no-brainer but it is not. 95% of whitened beeswax sold in Europe as pure actually are mixes with other cheaper waxes such as paraffin. Europe is a net importer of beeswax, controls on waxes are expensive, and distributors-wholesalers out of ignorance or sloppiness do not label products correctly. Beeswax mixed with paraffins for encaustic painting leads to very opaque milky and does not harden over time. It is preferable to use an unbleached yellow purified wax than an adulterated beeswax. Second, you will need damar resin (not to be confused with damar varnish) of the best quality that icomes in large crystals. Lastly, and only if you want to pigment the beeswax, you will need fine-art pigments, only fine-art pigments that do not degrade and / or emit toxic vapors with heat can be used.
In addition, you will need a support for encaustic paint that is both absorbent and rigid, usually used panels with gesso. Gesso is nothing but a mixture of plaster and binder, the main properties of a plaster is to have a good adherence to the support and good adhesion to the paint. The blend may also include pigments, usually titanium white, but, in principle, any pigment or colorant in the proper proportion could be used. The gesso for encaustic should be more absorbent than the one used for oil painting or for acrylic paint.
To receive exclusive content you need to
The term “wax” refers only to a substance having the following properties:
- Is solid at room temperature
- It melts at a relatively low temperature
- Solidifies when it cools
- Not soluble in water
There are waxes of vegetable origin such as soybean wax, carnauba and candelilla waxes, of animal origin like that of bees and derived from petroleum like paraffin. Each wax has its own characteristics that we will see later, except those derived from petroleum that are manufactured “to measure” according to the industrial use to which they are destined.
The wax … of bees
Beeswax is by far the most used wax as a material in encaustic paint.
Bees manufacture wax to build hives, honey feeds bees to make the wax. The worker bees consume between 3-4 kilos of honey each to produce a single kilo of wax, hence the high price of beeswax.
The bees initially produce white wax that is gradually contaminated. The dirt, the pollen and, especially, the propolis which is what makes it yellow. The color of virgin wax therefore depends on the age of the hive, the older the hive the darker the wax.
Apis melífera is the European bee and produces what we know in Europe as standard beeswax, but there are Asian, African bees whose wax is also sold in Europe. With the opening of the Chinese borders, to Europe arrives every year tonnes of Chinese beeswax, which is cheaper and often poorly labelled in terms of composition.
The formula above is the formula of beeswax is, for us basically means that it is formed by oxygen, hydrogen and carbon in different proportions and joints.
- Float in the water,
- It is quite hard in solid state,
- It softens around 40 ° C
- Fully melts at 62-64 ° C.
- It can burn when set on top of 200 ° C
To raise the temperature of beeswax by 1 ° C, it requires twice as many calories as to increase that same degree any kitchen oil. It consumes a lot of calories just to melt without increasing temperature.The structure of the beeswax is crystalline, the main process of re crystallization lasts 3-4 months (but the complete crystallization lasts up to a year)
Commercial beeswax is obtained by filtering the raw wax. Traditionally the raw wax was kept in cloth sacks inside fire water containers. With the heat the melted wax goes up escaping the fabric and the dirt was kept inside the sacks.
Chemical extraction (with solvents) is possible, but pollutants, pollen and propolis dissolve, and the quality of the wax is affected.
The 100% filtered beeswax remains yellowish mainly due to the carotenes contained in the propolis. To get rid of this color, wax was traditionally exposed to the sun in very thin sheets for several days. Today, the most common whitening technique is chemical bleaching. Chemical bleaching changes the structure of the wax becoming more brittle as the chains of carbon molecules are shortened. This is, however, the usual process for food wax, cosmetics and pharmacopoeia. The beeswax for pharmaceutical use in the United States is called the USP, in Europe as food additive E 901.
There are many types of waxes similar to beeswax, all of which are easier / faster to produce than beeswax and, of course, cheaper.
Mineral waxes are petroleum derivatives and, since the oil crisis in the 1970s, and have been subject to huge investment in research and technological development in Western countries. Today’s labs are able to produce “tairor-made” oils, waxes and pigments as needed. They can select in their production the melting point, density, viscosity, color, etc., that is required. Microcrystalline wax, for example, is manufactured to melt in the range of any temperature between 60-94 ° C.
Most of the beeswax being sold in Europe comes from China. Below you can find an FAO report on the import of beeswax – export figures are for 2005. Europe imported 6873 tons in 2005 export in the same period was 2167 tons, which means an annual deficit of over of 4,500 tonnes. Asia exported 5213 tons, 90% of which came from China.
The possibility that the wax you are buying in Europe is Chinese is high. And will you ask yourself , can it be used for encaustic? if it is pure yes, the problem is that the waxes that come from China come without certification and even without labelling …
Resins are solid, or highly viscous substances of plant origin, that harden in contact with the air. In encaustic paint resins are used for two purposes: harden the finish and keep the wax viscose for longer time increasing the melting point.
The damar resin
Damar resin is a natural resin obtained from trees in tropical forests. The name of Damar comes from the name of an Indonesian island. The damar resin is pale yellow-transparent. It has a very high Refraction Index so that through it the colors seem highly saturated. In fact, the damar resin is used as the main ingredient of varnishes for oil painting and tempera. Materials with higher refractive index (IR) are usually brighter than those with low IR because more light is reflected. The diamond, for example, has an RI of about 2.4 and the damar crystals are about 1.5 (in the same range as glass).
In Germany the damar resin is known as cat’s eye resin. The resin of damar is also highly appreciated for its use as incense, it is said that it raises the spirit and fights sadness and melancholy, illuminating the soul (and they are not wrong …). The optical qualities of damar resin crystals are what gave him the nickname of the cat’s eye.
The damar resin contains: 62% resin, 23% dammarol-like acid and 2.5% water. It is especially used in varnishing (*) because of its low molecular weight, its viscosity and high refractive index, which makes the colors appear highly saturated.
In Europe the damar resin crystals come mainly from Malaysia and Indonesia, and are classified in 3 degrees I, II and III according to their transparency and color and then sorted by size of the A (large crystals) to F (dust). Dirt, twigs, stones and other impurities are always present in resin crystals. Damar resin has a low toxicity, but the powdered resin can cause allergies (!).
Why is damar resin used in encaustic paint
The damar resin improves the workability of the wax by increasing its melting point. The damar resin, in addition, gives the wax the optical property of the varnishes to show highly saturated colors.
The damar crystals begin to soften at about 90 ° C and melt completely at 180 ° C. When we mix 1 part damar with 5 parts beeswax, what we are really doing is to combining elements with different melting points: beeswax 64ºC and damar resin 90ºC, increasing the melting point of the paint approximately 10-15ºC.
Basically, a pigment can be any substance that has the following characteristics:
- It can be ground very thin, without becoming too abrasive
- Have an intense color
- Do not lose your color when mixed
- That it is relatively weather-resistant to light and heat
- That is insoluble in the binder and chemically stable
The difference between pigments and dyes
Most pigments are dry dyes usually ground in a fine powder. The dyes are also dyes, which dissolve in the medium and color dyes of the materials by means of a chemical reaction. The dyes usually have a specific chemical composition for use with each material (especially textiles, hair fibers and plastics).
The dyes usually have less permanence of color and are more easily degraded by the effects of UV rays. It is the case of the inks of the markers for example.
The first pigments used were of mineral origin, ocher, red, charcoal black and blue – lapis lazuli, or of organic origin from insects and molluscs such as carmine. With the industrial revolution synthetic pigments began to be manufactured in laboratory, like Prussian blue or the whole range of cobalts. Already in the twentieth century, with the development of organic chemistry appeared “organic” synthetic synthetic pigments with very high coloring power.
Some of the pigments used throughout history today know that they were highly toxic such as lead white or vermilion (mercury). The degree of toxicity of pigments derived from cadmium is controversial, so it is a good idea to avoid them as much as possible.
Properly handled the use of powdered pigments presents no greater risks than that of any other human activity. Attach the link of our store code of good practices for the handling of pigments.
Color, color intensity and brightness
Particle size of the pigment plays a key role in the color attribute, pigments with smaller particles have a larger surface exposed to light, giving them a greater power dye.
Opacity or transparency
What primarily makes a color transparent is the ability of the pigment to disperse light. The smaller the pigment particles will disperse the light more effectively.
Inorganic pigments have a high refractive index and organic pigments have much lower values. Consequently, most inorganic pigments are opaque, while organic pigments are transparent.
There are pigments that create unusual absorbency and dispersion effects. This is an area where much development work in the pigment industry is still ongoing.
Fluorescent materials absorb light at one wavelength and emit light energy at another. Often, light energy is absorbed in the UV range, outside the visual range, and emitted in the visual range. Optical brighteners used in paper and textiles are some examples.
Metal pigments usually contain aluminium or other flake metal that acts as tiny mirrors change the perception when looking at the sample from several angles.
Pearlescent pigments generally contain semitransparent mica flakes that allow some light to pass through their surface and absorb and scatter light. The final effect is the duplicity of light waves, creating a multi-colored effect, such as oil in water.
Light resistance of pigments
Many materials are particularly sensitive to light, especially organic materials such as paper, fabrics and organic pigments being prone to discolouration. The origin of the discolouration is found mainly in light and ultraviolet (UV) radiation. Sunlight for example provides the energy needed to trigger the chemical reactions that lead to discolouration in dyes and pigments. But not all pigments are discoloured in equal measure, in fact there are pigments resistant to light and we will see how to know.
Not only the light resistance of the pigments is important, but also the binder influences this resistance. Beeswax protects pigments against ultraviolet light, which makes encaustic paint especially resistant to light.
There is a method for qualifying the light resistance of pigments by comparing the dyes with a standard of indigo blue dyeing. At present, this method is common practice in Europe for classifying light-resistant pigments. This standard compares the results of the dyeing of wool with the indigo blue, classifying the results from value 1 (fugitive) to value 8 (very resistant to light = indigo). Level 2, for example, takes twice as long to fade as 1. Level 3 is twice as long as level 2, and so on. Today pigments are much more resistant to light than indigo blue but without
In the United States the light-resistant pigments are classified into 3 levels that you will have seen if you use American brands like Golden, Liquitex, or R & F …
The American classification is:
ASTM I – Excellent resistance
ASTM II – Good Strength
ASTM III – Insufficient resistance to use in fine arts
OUR FAVOURITE POSTS
Notes & Multimedia content
¹) Beeswax rendering video
²) Interesting video on how damar resin is extracted (indonesian language)
³) The materials collection, at the Harvard Art Museums in Cambridge, MA,
This post is also available in: Spanish