I have thrown away at least six paint brushes that could have been saved. I would finish painting, leave the brush in the sink “to clean later,” and later never came. The next day the bristles were a solid block. Into the trash.

A good brush costs $15-20. Throwing away six of them is over $100 in the garbage. Here is how to clean them so they last through dozens of projects.

Latex Paint: Water and Soap

Latex (water-based) paint is the easiest. Rinse the brush under warm running water until the water runs mostly clear. Then put a drop of dish soap in your palm and work it into the bristles with your fingers, rinsing and repeating until no more color comes out.

The key is getting the soap into the metal ferrule — the band where the bristles meet the handle. Paint hides in there and dries, splaying the bristles outward over time. Massage the soap into that area specifically.

Final rinse in warm water, shake out excess water, reshape the bristles with your fingers, and hang or lay flat to dry. Never store a wet brush standing on its bristles — it will dry crooked and never paint straight again.

Oil-Based Paint: Mineral Spirits

Oil paint requires mineral spirits or paint thinner. Pour a small amount into a container — an old jar works well — and swish the brush around. You will see the color clouding into the spirits. Pour out the dirty spirits and repeat with fresh spirits until they stay clear.

After the spirits, wash with warm soapy water to remove the thinner residue. Reshape and dry as above.

Work in a ventilated area. Mineral spirits fumes are not something you want to breathe for long.

How to Save a Brush You Already Ruined

If the brush is already crusty with dried paint, soak it in white vinegar heated on the stove until hot but not boiling. Submerge only the bristles — not the ferrule, as soaking can loosen the glue holding the bristles. Let it sit for 30 minutes, then work the bristles with a brush comb or old fork. Rinse and repeat until the paint softens enough to comb out.

This has saved three brushes I had written off as dead. It does not work on every brush — if the paint has fully hardened inside the ferrule, the brush is probably done.