I just pulled out my kids' paintbrushes that we haven't used in quite a while, only to discover the source of the SMELL that has been coming from my paint basket! Our paint brushes had MOLDED. Who knew that was possible? They are mostly painted wood handles with a couple of those disposable sponge "brushes" with wood handles. The sponge ones were definitely the worst. After using them, I wash them, let them dry and put them back in the plastic Ziploc bag, and back in their basket. Obviously, I wasn't letting them dry enough. The mold was a sort of coppery colored powder that looked like tiny cauliflowers bursting all over it. I didn't take any pictures because I just THREW them all away! Even the plastic handled paint brushes had the mold all over the bristles. Very gross. I've been looking all over the internet to see if this has happened to anyone else, and am not finding anything, but still:
Tip of the day: STORE YOUR PAINTBRUSHES UPRIGHT IN A JAR!!