Auxiliaries to use with Cobra

Can I also add Cobra painting medium directly to the paint?

Cobra painting medium can be added directly to the paint. This makes the paint not only thinner but also creamier. Painting medium increases the durability of the paint.
This allows the artist to work according to the "wet-into-wet" principle; painting is continued as long as the paint is wet. If desired the medium can be made less creamier with water; just like the paint, Cobra painting medium can be mixed with water.

Cobra painting medium can be used for layered painting. A next layer can only be applied once the previous layer is dry enough to ensure that it will definitely not dissolve. In connection with the final durability of the paint film, layered painting has to follow the rule of 'fat over lean': each subsequent layer has to contain a little more oil. Water makes the paint leaner, medium makes the paint fatter. The first layer can be thinned with water. The next layers are thinned with a combination of water and medium. As the mixture contains increasingly less water and more medium, each paint film becomes increasingly fatter.

What is Cobra painting paste and what can I do with this product?

Cobra painting paste is a colourless and water mixable medium that can be mixed in any proportion with Cobra water mixable oil colours. The thickness is the same as that of the paint, and so the paste can be described as a water mixable oil paint without pigment. Cobra painting paste has various applications.

Increasing the amount of paint. Cobra painting paste can be mixed with the paint in any proportion. So for the Impasto techniques of more expensive colours more paint can be made without any change in the colour. The more paste that is added, the more transparent the result; this however is not, or hardly, visible in heavy layers, depending on the type of pigment. In combination with transparent pigments, transparent layers can be added with a glazing effect.
Decreasing the tinting strength. The tinting strength of a colour will decrease, proportionate to the amount of paste that is added. This can particularly be relevant with the alla prima (wet-in-wet) technique, if colours with a strongly different tinting strength are mixed on the painting. By adding more Cobra painting paste to a stronger colour, its dominance will be reduced.

Does a painting made with Cobra water mixable oil colours have to be varnished?

Yes, this final varnish slows down the oxygen absorption and consequently the aging process. This determines the eventual degree of gloss as well as protects the paint from atmospheric contamination.

Cobra water mixable oil colours dry like other traditional oil paints through the absorption of oxygen, which is a chemical process. Once the paint is entirely dry this oxidation process does not stop but continues in an ageing process. Eventually this can be visible as crackling. Once the paint is entirely dry (with layers of normal thickness this takes approximately one year, with very thin layers several months less, and with thicker layers several years) it is advisable to apply a final varnish. The oxygen absorption and consequently the aging process is slowed down.

How do you apply varnish using a spray can?

Ensure that the paint is fully dry; with thin to normal layer thicknesses this is up to approximately one year, with thicker layers this can be several years.

The matt and the satin contain matting agents that fall to the bottom in the varnish and therefore have to be shaken well before use. This is to avoid any differences in gloss.

Ensure that both the painting and the varnish are at room temperature. It is best to lay the painting flat (with ample space on a piece of cardboard or newspapers). Do not hold a spray can horizontally (do not point downwards) but spray forward so that a mist of varnish descends upon the painting.

If a painting that is already a few years old is going to be varnished, the surface of the painting is first made free of grease using a cloth with some white spirit. This removes dirt from the canvas and paint film becomes somewhat open. The varnish will then bond better.

I have heard that you may only apply a final varnish after a year. Is it really not possible to do this any earlier?

No, this cannot be done any earlier unless the paint film is very thin. An oil painting of normal thickness can be varnished after approximately one year. In the case of very thin layers, several months earlier, but in the case of thick layers this can be a number of years.

If the varnish is applied too early then there is the risk that the solvent of the varnish will dissolve the oil paint that has not yet dried, and bring this to the surface. If this happens, the painting may remain sticky for many months, even years, and it would be difficult to stop dust adhering.