Cobra water mixable oil colours are ideally suited for working with painting knives.

Use of painting knives

Painting knives are usually used for unthinned paint, often for applying thick dabs of paint (impasto). Use the underside of the knife to mix the paint on the palette, to take the paint off the palette and to apply it onto the canvas.

Painting knives are available in various shapes and sizes. Every knife has its own possibilities.

A few words of advice:  

• Rest the index finger on the raised part of the knife, which will help to keep the fingers clean.
• Take paint off the palette as if you are taking butter for a sandwich.
• Use the entire length of the knife, and not only the point.

Mix the paint toward you, as this gives you a better feel for what you're doing.

Acrylic colours:
Under the name "Amsterdam Acrylic Remover" Royal Talens supplies a solvent which can dissolve dried acrylic paint. 
Pour as much solvent into a glass jar or bottle to cover the hair bundle and some of the ferrule. Allow the brushes to soak for approx. one hour, clean them with water and soap and then rinse with water.

PLEASE NOTE: Do not add too much solvent as the varnish of the handle can also dissolve! 

Acrylic Remover is completely biodegradable.

Oil colours:
Dried oil paint can only be broken down in very aggressive solvents such as xylene. Due to the hazards posed by these solvents they are not sold by Royal Talens. The long drying time of oil paints gives the artist plenty of time to clean the brushes. 

Brushes can best be cleaned in the solvent that is also used for the paint. Depending on the type of paint, this can be water or white spirit.

• Watercolour, gouache, poster paint, Ecoline, water mixable oil colours and acrylic colours are cleaned with water.
• Oil colours or alkyd with white spirit.

The squirrel hair watercolour brush has very fine, soft hairs. Extreme moisture absorption. Very vulnerable.

There are many expensive agents to clean brushes, but a mild neutral hand soap, green soap or washing-up liquid also work very well.  

Brushes made of firmer types of hair are the most commonly used for acrylic painting.   

Hog hair brushes can hold a lot of thick paint, but have a brush stroke that is too inaccurate for working in fine detail. What's more, with water hog hair brushes become a little less resilient. 

Synthetic (selected filament) brushes are not affected by water and are suitable for both thick and strongly diluted paint as well as fine details. 

Almost all types of hair are suitable for gouache, with the choice being more to do with the technique used.

If the paint is used pure, then hog hair brushes are best.

If the paint is thinned (strongly) with water then brushes with softer hairs such as ox hair and (kolinsky) sable should be used.

In all cases, polyester brushes (selected filaments) offer an excellent alternative.  

Brushes made of hog hair are the most commonly used brush for oil painting, although other brushes are preferred for certain painting techniques.

• The firmer hog hair 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 and iltis hair (imitation) brushes are highly suited.
• For all techniques, however, brushes made of synthetic fibres (selected filament) are a good alternative.  

Brushes are available in different price categories and qualities.

• The Rembrandt brushes are made completely by hand and provide the highest possible quality.
• Van Gogh brushes, also made by hand, are attractively priced and of an excellent quality.
• Talens brushes provide a good quality at very competitive prices.  

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

The softer types of hair can hold a lot of water and are therefore used as watercolour brushes.

Depending on the type of hair, there are brushes in a wide range of qualities and price ranges.

Brushes made of pony, goat and ox hair and selected filament brushes are very affordable. More expensive brushes made of squirrel, red sable and red Kolinsky hair are of excellent quality.  

What brushes you need for water mixable oil colours depends on the technique applied and your personal preference.