I have experimented with numerous soaps to clean oil paint out of brushes, from art shop soaps to a plain old bar of vegetable soap. Art shop soaps are always ridiculously expensive and I always end up using it really quickly – and they aren’t necessarily very good anyway. Bars of soap work OK but it is hard to work the soap into a lather – especially on large brushes.
Recently I experimented with using dish washing detergent. It works fantastically and is so cheap – about $3 for a large bottle! Because the soap is already a liquid you can just dip your brush into it and it works into a lather extremely easily. The oil paint comes out so easily. After all, dishwashing detergent is made to remove fatty oils from plates and cutlery.
I recommend storing the soap in a large container so you can easily dip brushes to coat with detergent.
My method of final clean up at the end of the day is a quick rinse of the brushes in odourless solvent which removes 95% of the paint then a quick clean in the detergent to remove any remaining paint.
People also claim that wiping the brush, then working some regular vegetable oil into the brush and wiping it again, removes much of the pigment. Then it is easier to wash with soap and water.
I used to use this technique and found it to work rather well with small brushes and smaller quantities of paint. However, when painting large canvases and using large brushes and large quantities of paint I found it quite difficult to remove all the paint from the brush using this technique. This was especially apparent when trying to clean white paint out of a brush to then use without contaminating another colour.
To get around this problem I now I have a totally sealed container filled with odourless solvent with a grill inserted in it. I use a rag to clean brushes most of the time while painting but when I really need to fully clean a brush I quickly open the container of solvent and rub the brush against the grill. The grill sits about 2cm above the bottom which allows all the paint pigments to fall through to the bottom of the container while leaving the solvent on top clean.
This method allows me to use solvents as little as possible and they last within the container for a long time without needing to be changed.
I use baby wipes they are great for cleaning brushes to change color or at the end of painting session ,then a liquid cleaner .
Have you tried Murphy’s Oil – it cleans out deep seated paint, and revives stiff brushes. Very effective.
I love Murphy’s oil- at $2 Cdn for a 475ml bottle- it lasts for a long time and it does a wonderful job on my brushes.