HOW TO MAKE pAINT?

As was stated in the article “what is paint?”: making paint doesn’t have to be complicated. All there is to do is to forget about the universal ingredient that is pigment and make logical what the binder of the technique is. Once the logic of that binder has been understood, all that is left to do is mixing pigment and binder together in the right way.

I. OIL PAINT AND LINSEED OIL 

The binder of this technique is linseed oil. Now, what is the main characteristic of linseed oil by which we can understand it’s “logic”? Unlike other vegetable oils such as canola or olive oil, linseed oil reacts with oxygen (a process called oxidation), to slowly go from liquid to gel to a tough solid form, therefore we refer to it as siccative oil because it solidifies through oxidation. Linseed oil is not the only siccative oil and is therefore not the only oil we could use, poppy seed, safflower or walnut oil are all semi-siccative oils, but, generally, we avoid using them as our “main” grinding oil because they will to dry slower and form a less flexible paint film than linseed. Another important aspect besides the fact that linseed oil oxidizes rather than dries is that this oxidation doesn’t stop when the paint is dry, but continues on for years after the painting has been painted, varnished and sold. So, the second important aspect of oil paint is that it is a dynamic technique in this respect and that it still continues to transform (i.e. react, oxidize) after the painting has long been finished.

Making oil paint      
(you can also view the Demos section)

To make oil paint yourself all you need to have is painting knives, a square piece of glass that can be maintained on a steady table, pigments and linseed oil. Take whatever quantity of pigment you need for the painting session and put them on your piece of glass, then gradually add just the necessary amount of oil needed to wet the pigments as you mix with your painting knife.

Once the pigments are all wetted you should have something that somehow resembles oil paint but has a lot of lumps, so the second part of the process is to disperse the pigments. To do that you just keep on mixing, what happens as you mix is that the lumps (better called aggregates) of pigments are gonna get smaller and smaller: the pressure of the knife will break the tendency of pigments to cling together and, as it does, you should notice a change in both color and consistency.

We recommend that you to use a muller when doing a large batch of paint or when an ultra-fine quality of paint is wanted, but, for small quantities a palette knife does a great job.

The use of extenders in oil paint      

Extenders or fillers have long been used in the making of oil paints. Though we might think of it as a negative thing, as adulteration, extenders do have a lot of virtues, and, if used in reasonable proportions they will allow economy and control over the painter’s materials. barium sulfate and alumina hydrate are the most common of “extenders” and are considered as white pigments: Pw21, Pw24. When adding any of those two pigments into your paint, you will obtain ab geater quantity of paint, without affecting the color because they have virtually no tinting power. Here is a concrete example. We want to make cobalt blue oil paint and we decide to replace 1/4 of the amount of pigment with barium sulfate. What will happen is that without any significant color change, and still arriving with the same amount of paint in the end we will have saved close to 1/4 of whatever this paint would have cost to do without extenders because the price of barium sulfate is a fraction of the cost of cobalt blue. So if you had a pound of any expensive pigment and systematically mixed it with extender in a 1:3 ratio, it is as if you had bought 1 pound and a quarter of that pigment, but that extra quarter only cost you a negligible amount of money.

Of course economy isn't everything, we feel that the use of extender-free oil paint is well worth trying as the cost of making it yourself is so low in comparison with the price of ready-made artist's color.

Consistency of oil paint      

When grinding dry pigments, you may realize that some colors will lose their consistency after a while. It is a normal phenomenon and in no way should a pigment be considered of low quality because of this. Ultramarine blue is the most stunning case of unstable consistency, when ground by itself and left to stand on the palette it will change from stiff oil paint paste to become liquidy and stringy.

The solution to this problem is to add a stabilizer to the paint. Wax, and especially beeswax have long been used in the industry for this purpose, so we recommend that you do the same. Our experience is that a cold wax medium (see the recipes section) works very well for this purpose and is easier to incorporate in paint than raw wax.

II. ACRYLIC PAINT      

The binder of acrylic paints is acrylic polymer emulsion. Unlike siccative oils that oxidize, this emulsion of plastic resins dries by the evaporation of the water and solvents it contains to form a tough & flexible film. It can be purchased as gel or gloss medium, modeling paste and so on, each is acrylic polymer emulsion, but something else has been added to make them mat or glossy, thick or liquid. One thing to which you have to pay attention is whether these mediums are designed to be opaque or transparent. In some acrylic mediums either fillers or white pigments have been added in order to make them opaque, they can be used when an opaque paint is desired but attempting to glaze with such mediums would certainly be frustrating, if not impossible.

Making acrylic paint      

Certainly, the easiest way to make good acrylic paints is by using a dispersion of pigments. When making oil paint we have all the time that is needed to disperse the dry pigments. Also, the linseed vehicle, because of it’s chemical nature, contributes to the dispersion of pigments. But with acrylic polymer emulsion, the available mixing time is very short and even when pre-mixing dry pigments in water and adding it to the acrylic, it is very difficult to obtain a paint that will be well dispersed and totally free of lumps. Dispersions, on the other hand, are pigments already dispersed to their fullest degree in water, therefore they mix with acrylics in moments, eliminating the long and often unsatisfactory pre-mixing of pigments.

III. GOUACHE AND WATERCOLOR      
(you can also view the Demos section)

The binder for gouache and watercolor is gum arabic. which comes naturally from acacia trees. We have a good recipe to make your own gum arabic solution in our recipes section, we suggest you take a look.

To make your own watercolor we again recommend that you to use the dispersions of pigments which is even more important in that technique. By adding drops of dispersions in the solution, you will instantly obtain transparent watercolor. To get an opaque gouache, simply mix either talc, zinc white or china clay into a paste using the same solution and add your dispersions or pigments.