FAQ: Water-Mixable Oil Paint Auxiliaries
This is not recommended. The surface of both products is too closed, so that the oil can hardly or not at all anchor itself in the acrylic film. The adhesion of the oil film will not be sufficient.
All surfaces that are free of grease and are somewhat absorbent, such as paper, cardboard, cotton, linen and wood, can be prepared with Gesso. With an open woven canvas, it is recommended to apply a layer of Amsterdam acrylic binder first. This seals the meshes of the canvas so that the Gesso does not come through at the back.
Cobra Painting medium can be added directly to the paint. The paint then becomes thinner and fatter. Painting medium increases the durability of the paint film. In this way you can work 'wet in wet'; painting as long as the paint is wet. If desired, the medium can be made less greasy with water; just like the paint, Cobra painting medium is water mixable.
Yes, the oxygen absorption and thus the ageing process is slowed down by a final varnish. At the same time, the final gloss level is determined and the paint is protected against atmospheric contamination. Cobra water-thinnable oil paint dries like traditional oil paint through the absorption of oxygen, a chemical process. After the paint is completely dry, this oxidation process will not stop and an ageing process takes effect. Eventually, this can become visible as crackling. After the paint is completely dry (with normal layer thickness about one year, with very thin layers several months earlier, with thicker layers several years) it is therefore advisable to apply a final varnish. Oxygen absorption, and thus the ageing process, is slowed down by the varnish layer.
Cobra painting paste is a colourless and water mixable medium.
Preparation:
Make sure the paint is thoroughly dry; with thin to normal layer thickness, this takes about a year, with thicker layers several years.
If a painting is to be varnished that is already several years old, the surface of the painting can first be wiped with a cloth to which some white spirit has been applied. This removes the dirt from the canvas and opens the paint skin slightly. The varnish will then adhere better.
Steps in varnishing:
• Matt and satin varnishes contain matting agents that sag in the varnish and should therefore be shaken well before use; this is to avoid gloss differences.
• Make sure that both the painting and the varnish are at room temperature.
• It is a good idea to lay the painting flat (generously on a piece of cardboard, plastic or newspaper).
• Hold the spray can horizontally (do not point downwards) and spray forward so that a mist of varnish descends on the painting.
No, unless the paint layer is very thin, it cannot be done earlier. An oil painting can be varnished after about a year for normal layer thickness, a few months earlier for very thin layers, and several years for thicker layers. CAUTION: If a varnish is applied too early, there is a risk that the solvent of the varnish will dissolve the oil in the paint that has not yet fully dried and bring it to the surface. If this happens, the painting may remain sticky for many months or even years, and dust adhesion is difficult to prevent.