A history of egg tempera painting
     Tempera painting predates the popularization of oil painting. The process was named for the technique of preparing (tempering) dry pigments with egg yolk and distilled water. Until the discovery of oils, all easel painting was done using tempera paints on wooden panels. Once oil paints became popular, tempera was mainly used as an underpainted base coat for oils. As tempera needs a solid support, its use also waned as canvas became more popular.
     Despite this lack of flexibility, tempera work has a depth that can be lacking in acrylic or oil works. Due to the transparent nature of the medium itself, layers can be built upon each other without sacrificing quality. While many manufacturers market ready-made tempera colours, these are usually goaches or body paints. When buying tempera paints, be sure to specify "egg tempera".

Making your own
     To increase the colour range, many artists prefer to make their own tempera paints. Traditional tempera is made by mixing finely ground pigment with egg yolk, distilled water, and sometimes linseed oil and varnish to increase the workability. While any pigment can be used, opaque pigments such as cadmiums and artificial pigments work well. Since they are used thinly and combined with the egg emulsion, these pigments will appear semi-opaque, giving the painting body while retaining its translucency.

Preparing the emulsion
     To maximize workability, use only fresh eggs. The colour of the yolk has no impact on the colour of the paint. Use glass or ceramic containers to avoid contamination, as these can be washed easily. Because tempera is fast-drying, only a small amount of paint should be mixed on a palette at one time. Tempera dries too quickly to be mixed on the support. Unlike other paints, tempera cannot be stored for use later. Generally, one yolk is enough for a days work.
     Gently break an egg and seperate the yolk.
     Remove the white by rolling lightly in your hand or on a paper towel.
     Puncture the yolk and drain into a glass jar or dish. Discard the sac.
     Mix yolk with a little distilled water using a plastic palette knife.
     (Do not use metal tools as these will contaminate the emulsion.)

Pigments
     Pigment is sold in a finely-ground form. Mix the pigment with a little distilled water into a paste with a palette knife, or place the pigment into a small jar with a little distilled water and shake to blend. This is then added to the emulsion a little at a time on a clean surface or palette using a plastic palette knife. The amount of pigment added depends on the colour you are using as some colours are more intense and require less pigment. Experimentation is the best way to learn the proper balance.

Emulsion Recipe One
     3 parts egg yolk
     3 parts distilled water
     1 part linseed oil
     Add the oil to the yolk one drop at a time, stirring between. Add the
     distilled water, one drop at a time, stirring between.
Emulsion Recipe Two
     3 parts egg yolk
     3 parts distilled water
     1 part damar varnish
     1 part stand oil
     Add stand oil to the yolk one drop at a time, stirring well. Add the
     distilled water and varnish and stir well. When dry, this emulsion
     creates a smooth, hard surface that can be buffed up to a slight sheen
     with a soft cloth.

Using Tempera
     Applying tempera is a process of layering, and the techniques used are dictated by the medium. The quick drying time precludes working on a large scale. As with oils, tempera should not be used in a single, thick layer. The paint must be built up in thin washes glazing over each other to consolidate and set properly. Tempera can be used on many supports including canvas and paper, but the traditional support is an inflexible board whose surface has been primed with two or more coats of white gesso.
     Similar to watercolour, tempera should be used in thin, semi-transparent glazes. These can be washed on loosely to quickly block a work, or, in a controlled way to build up specific areas. If the work is on a white gesso ground, a thin glaze will soften the background.

Tempera Accessories & Supplies
     Most accessories used for other mediums can also work well with tempera painting. Because tempera is quick drying medium, special attention must be made to keep tools clean. Some artists prefer to keep seperate tools for tempera.

Brushes used in other media work equally well with tempera, however, softer brushes used for watercolour work best. Do not let the paint dry on the bristles, as this will ruin the brush.

Plastic palette knives should be used to avoid contamination.

Use a glass, plastic, or disposable paper palette for easy clean up.

If you prefer to grind your own pigments, or to soften pre-ground pigments, a glass muller and slab can be usfeul. When working with dusty pigments, even those labeled "non-toxic", a protective mask should always be worn. The best masks have replaceable cartridge filters for use with dust or vapours.