While this is technically possible, the long-term results are not known.

Traditional oil colours and Cobra can be combined to a maximum ratio of 1/5 (i.e. up to 20% of traditional oil colours). Up to a ratio of 1/5: oil 1/Cobra 5. 

Yes, Cobra oil colours can be used for all oil painting techniques. - Painting alla prima (wet-on-wet painting) - Layered painting - Glazing - Impasto painting.   

Oil colours have a fat and smooth surface, on which the Gesso does not adhere properly.

Paints may never be flushed down the sink. All products containing paint must be disposed off as household hazardous waste.

The system of "fat-over-lean" (or: flexible over less flexible) must be followed if a painting is built up of various layers.

This rule must be applied to ensure adherence of the individual layers.

The underlying layer must be absorbent enough to allow the subsequent paint layer to bond.

This cannot be avoided and is caused by a combination of the colour used, the type and amount of thinning agent added and the absorption of the ground.

Sunken in areas may occur while painting: the paint becomes matt and the intensity of the colour reduces.

The differences in gloss can be repaired using retouching varnish.

Oil colours dry under the influence of oxygen, heat and light. The drying process, therefore, requires sufficient ventilation as well as light, and the room must be at room temperature. The drying can also be accelerated by adding a siccative or a quick-drying medium to the paint.

To allow oil and water to mix, an additive is needed. This additive helps to form a stable blend of small oil droplets in water. This blend is called an emulsion. The additive is known as an emulsifier.

 Working with Cobra has the following advantages: 

• no harmful solvents, like spirit and turpentine, are needed, which is better for your health and the environment
• easy to use (water and water mixable mediums)
• brushes and other tools are easy to clean with water and soap
• 100% retention of brush stroke/structure 
• no colour change from wet to dry 
• all colours have the highest degree of lightfastness +++ (at least 100 years lightfast under museum conditions)
• suitable for all oil paint techniques (alla prima and wet-on-wet)

Cobra is a genuine oil paint. The paint is made on the basis of drying oils and does not contain any water. An unusual property of this oil, however, is that it can be mixed with water.

The paint can be used in all the usual oil paint techniques. Very high-quality pigments are used for this product range.

Cobra is available in the grades Cobra Artist and Cobra Study. Cobra Artist has a higher pigment content. Both grades have the highest degree of lightfastness +++ (at least 100 years lightfast under museum conditions).

It is pleasant working with Cobra water mixable oil colours as you do not have to use any white spirit. Brushes and palette knives can be cleaned simply using soap and water.

With Cobra water mixable oil colours you can paint in the same way as with traditional oil colours.

When painting with traditional oil colours, the harmful solvents white spirit or turpentine are used in the underlayers.

With Cobra oil colours you can use water instead. Water replaces white spirit.. In this way you can work without solvents, so that your working space is kept free of that unpleasant odour of solvents.   

A number of factors determine whether paint can be referred to as Artists' Quality.
Firstly, the amount of pigment is important. Cobra Artist has a higher pigment content than Cobra Study.
Secondly, an Artists' Quality assortment has a wide choice of colours.
Lastly, the fineness is important. The ingredients in the paint must be distributed as well as possible. This requires more time in production.

"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.  

Mixing with water can be done in two ways:

• Thin the paint a little with a small amount of water. Here the water and the paint have to be mixed well little by little to acquire a homogeneous mixture. The emulsion between water and oil does not occur spontaneously, but needs to be stimulated.
• Add water to a little bit of paint to create a very thin and transparent paint with a watercolour effect.

However, if a huge amount of water is added, then the greatly thinned oil does not produce enough protection for the pigments. For a first sketch where later thicker paint or paint thinned with medium is used to paint over it, this is no problem.

If a painting is made only with very thinned paint, it is recommended to add at least 20% Cobra Painting medium to the water. 

Technically-speaking the difference lies in the binder.

With alkyd paints this is an alkyd resin dissolved in white spirit. With Cobra water mixable oil colours this binder consists of drying oils.

Its use results in the following differences:

• Alkyd paint dries considerably faster than Cobra water mixable oil colours, as a result of which there is less time to work wet-on-wet.
• Solvents are necessary for alkyd paint in order to thin the paint and clean the equipment.
• For Cobra water mixable oil colours no volatile solvents are necessary. Water can simply be used.
• With the use of pure alkyd paint, the brush stroke is more flowing.

When using pure Cobra water mixable oil colours the brush stroke remains 100% during drying.   

All grounds that are free of grease and are somewhat absorbent can be used as a ground for painting with water mixable oil paint, providing this has been prepared with a universal primer.

The stretched canvas is usually already given this preparation.

Untreated grounds, such as paper, cardboard, wood, cotton and linen, can be prepared with Talens Gesso 1001. This is an excellent universal primer based on pure acrylic. 

When preparing an open woven canvas it is recommended to first apply a layer of Amsterdam acrylic binder. This seals the mesh of the canvas so that the Gesso does not penetrate through to the rear.

If Cobra is thinned with water, universally primed canvases are the best choice. If water is not used, then it is possible to paint on canvases that have been prepared in the traditional way using an oil-based primer.

All grounds that are free of grease and are somewhat absorbent, such as paper, cardboard, wood, cotton and linen, can be prepared with Gesso.

When preparing an open woven canvas it is recommended to first apply a layer of Amsterdam acrylic binder. This seals the mesh of the canvas so that the Gesso does not penetrate through to the rear.

Oil paint does not adhere well onto metal, plastics and other non-absorbent grounds. The ground will first have to be treated with an adhesive primer or wash primer suitable for the ground in question.

We cannot guarantee the quality of adherence of the primer. Lightly sand the primer once dry and apply a second layer. Also sand this layer once dry and apply one or more layers of Gesso 1001. The ground is now ready for painting with oil paint.

This is not recommended. Both products have a surface that is too sealed, so that the oil can scarcely, if at all, bond on the acrylic film. Poor adhesion of the oil paint film would then result.

Both qualities use the same pigments. The differences lie in the amount of pigment and the fineness of the grinding during the production process.
Cobra Artist uses more pigment and the pigments are ground more finely during the production process.

Both Gesso and acrylic colours are made on the basis of an acrylate; the major difference is in the formula. Gesso is composed in such a way that it always retains an open structure that is ideal for the adhesion of both oil colours and acrylic colours.

Linseed oil has proven itself over the centuries as a binder with the best combination of properties. Because, over time, linseed oil shows a certain degree of yellowing, linseed oil is sometimes replaced by safflower oil, particularly for white paint.

This oil yellows less, but also has disadvantages: the drying time is longer. Safflower oil is, therefore, not suitable for pasty use and in undercoats. White based on safflower oil is used mostly in the top layer.

Cobra Artist and Cobra Study use the same, carefully selected pigments. This means that the lightfastness of both qualities is identical.

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.

275 primary yellow, 369 primary magenta, 572 primary cyan

The paint contains different ingredients. Contact us if you require specific information.

For Cobra colours you can use the same brushes as for regular oil colours. There are also brushes of the Cobra brand. These are brushes of ‘Selected Filament’ hair: resilient synthetic hairs. You can also use animal hair brushes, such as Kolinsky, red sable, ox hair and hog bristle.

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.

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.

Oil colours do not adhere well onto a sealed layer of acrylic colours. So, you cannot first make a painting with acrylic colours and then paint over it with oil.

There are, however, some methods you can use to obtain optimal results:

• Thin the acrylic colours with water and make a thin underpainting on a universally primed surface. Each painted surface now contains less acrylic resin. Once the water has evaporated, the paint layer is porous enough to allow the oil colour to adhere into the layer of acrylic colours.
• For the underpainting, use Gesso instead of white acrylic colour when mixing the colours. In order to ensure the adherence of the oil paint, each colour must be mixed with sufficient Gesso.

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.

The choice of brush depends on the painting technique.

Hog bristle brushes are most commonly used for oil paint. The firmer hog bristle brushes can hold a lot of thick paint, but have a brush stroke that is too inaccurate for working in fine detail.

For detailed work and glazing techniques, sable hair is highly suited.

For all techniques, however, brushes made of synthetic fibres (selected filament) are a good alternative.

Oil colour brushes have a long handle so that sufficient distance can be maintained from the painting.

Paint of certain colours can wrinkle when applied in thick layers, particularly cobalt, madder and earth colours.

The cause lies in the type of pigment and the resulting composition of the paint.

This wrinkling can be avoided by mixing the paint with Painting Paste. In order to avoid wrinkling a mixing ratio of 1:1 is sufficient. The colour and consistency of the paint remains the same, but the oxygen now has better access to the paint within.