Thoughtful brush care will keep your brushes in good condition for years. I’ve written out a few tips on cleaning brushes that have kept my most precious brushes in shape for over twenty years.
First rule and the most important: Cleanse brushes immediately after use and keep acrylic brushes moist when using them.
Cleaning brushes ultimately depends on what medium one is using. With water based paints, cleaning is more simple. Rinsing well with luke warm or cool water first, to remove as much paint as possible. Then, use a light cleanser, even dish washing liquid or shampoo will work. I even use Murphy's Oil soap on occasion. It conditions the brush a bit and the oil coats the brush so that it doesn’t retain the pigment the next time it is used. There are many other options for manufactured brush cleaners as well and some of these even will work to remove built up, dried on acrylic paint. Once the brush has been cleansed and rinsed well again, reshape the bristles with your fingers and dry laying down flat or hanging upside down if possible. Standing on end is okay, but water sitting down in the ferrule isn't ideal.
To remove oil paints, rinse well in the solvent used for thinning, such as turpentine or mineral spirits. Then dry as much as possible with a paper towel to remove the solvent before using a cleanser. Once again, use a light cleanser with water to finish removing all of the solvent. If you are adverse to using a solvent for rinsing, try removing the pigment with a vegetable oil first. (Don’t wash it down the drain of your sink, however.) Once the oil has removed the oil color in your brush, then use a cleanser to remove the oil.
Some inks can dry in the brush and be resolved the next time the brush is used in the ink, if the ink is a shellac-based product. Water based inks should be treated like water media in cleaning the brush.
From time to time you may also use hair conditioner in your brush to keep it supple and to prevent paint from sticking to the bristles. It is possible to reshape a brush if the tuft has been bent by washing and drying carefully. Rinse well, use a light cleanser and reshape the brush by hand. Then use newspaper wrapped around the tuft in the shape you want the brush to hold and keep in place with a rubber band. Allow the brush to dry completely before removing the newspaper.
There will come a time to purchase new brushes because the bristles have worn down or because paint has built up in the old brushes; and an artist can really never have enough brushes anyway. But keeping your brush supply in good, clean condition will make for better painting results.
To shop for some new brushes, check out the Dynasty Purchasing Page.