Oil colour tube 15 ml Permanent Red Light 370

The oil can simply be mixed with the paint on the palette.
The separation of the oil is caused by contact of the paint with oxygen. There's nothing wrong with the paint and you can use it as normal.

Drying process of oil colours

Oil colours are a chemically drying (oxidative) paint; the oil dries through absorbing oxygen from the air. This helps to link the molecules together in chains. (Ultraviolet) light is necessary to provide the energy for this.

The chemical drying of linseed oil takes more time than the physical drying of the other types of paint.

Depending on the thickness of the layer and the type of pigment, the paint layer is dry to the touch in approximately one to six weeks. The entire film is completely dry between six to twelve months. It can take very thick layers even several years to dry. Even then the uptake of oxygen does not stop; the ageing process now starts. Once the paint is completely dry it is therefore advisable to treat the painting with a final varnish. This helps to slow down the oxygen uptake and consequently the ageing process as well.

Please note:If a painting was varnished before it had time to completely dry, the paint beneath the varnish will remain soft for quite some time, as the varnish layer will have sealed the paint from oxygen, making it difficult for the paint to continue drying. In this case, should the varnish be removed the paint would also be able to (partially) dissolve.

When removing old varnish layers, care must be taken to prevent any problems during cleaning.

Step 1:

Take a flat brush of a few centimetres wide, dip it into white spirit (use white spirit 090 ONLY) and brush it over a surface area of around 15 x 15 cm.

Step 2:

Wait until the varnish begins to swell. In the meantime, rinse the brush and repeat the procedure over the swollen varnish. This will now partially dissolve in the white spirit contained in the brush.

Step 3:

Continue the procedure with a rinsed brush until all the varnish on this area has been removed.

Step 4:

You can then treat the next area.

Please note: Once the varnish has been removed it will appear as if there is a white film on the painting. This disappears as soon as a new layer of varnish is applied.

Our Amsterdam acrylic varnishes are also suitable as final varnish for oil colours, but do have slightly different properties.
- The gloss is somewhat different
- They are more thermoplastic
- They are more flexible

Differences between the Talens Acrylic Varnishes and Picture Varnishes

The Acrylic Varnish (glossy 114 and matt 115, for both oil and acrylic colours) is a final varnish, but does not have the same properties as the Picture Varnish (glossy 002 and matt 003).

The Acrylic Varnish is a solution of acrylic resin in white spirit, the Picture Varnish a solution of low molecular weight resin in turpentine (in the spray can white spirit).

Both types of resin do not yellow.

The 002 is glossier than the 114, the 115 more matt than the 003 (glossy and matt varnishes of this type can be mixed with one another to the desired degree of gloss).

The matting agent in the 003 consists of waxes that are dissolved in the turpentine; in the bottle the varnish appears crystal clear, but once dry shows an eggshell gloss.

The matting agent in the 115 consists of silicas (similar to pulverised glass); this varnish must be shaken well before use as the matting agent sinks to the bottom of the bottle. In the spray can the matting agent for both varnishes is silica.

For an even (matt) degree of gloss a varnish that contains a matting agent and that has been applied with a brush has to be brushed in one direction. The Acrylic Varnish forms a more flexible film than the Picture Varnish. This is of particular importance when using on acrylic colours, as this paint also forms a flexible layer.

Before a final varnish is applied a very thin layer of oil paint must have dried for at least six months, a layer of normal thickness one year, and thicker layers several years. If a dry layer of oil paint contains a lot of oil, it is advisable to wipe it with white spirit before varnishing to ensure good adherence.

"Alla prima" means that the painting is painted "wet-on-wet". With this technique the colours are mixed not only on the palette but also on the painting itself.

Painting therefore has to be carried out quickly; none of the colours may dry before the painting is finished. With this technique, the paint is always thinned with the same thinner or the paint can be used pure. If a thinner is used, the most durable result will be obtained if a good painting medium is used.