Originally Posted by wandrson
I was always taught not to leave my brushes in solvent while painting (learned in oils) and never had a problem. While working with watercolors, paint drying on brushes during the painting session isn't a problem; however, I am confused how to deal with this in acrylics.
There are two things that I do to avoid the dried-paint-in-my-brushes problem. I have a home-made brush tray with a wet sponge in one end that I lay my brushes on when they are not in use. I'll see if I still have a photo of this rig to help explain it:
If this photo shows up, you can see that the tray is not very deep and the wet sponge is not as thick as the tray is deep. I lay the heads of my brushes on the wet sponge and the handles rest on the opposite end. This angle is just enough to keep the brush heads on contact with the wet sponge but not enough to bend them or distort their shape.
NOTE: I usually wipe any excess paint from the brush first, then give it a quick rinse to get most of the paint out of it before I place it on the sponge. This helps keep the sponge from getting messy.
No matter how long my painting session is, this rig will keep my brushes moist and prevent the paint from drying in them.
When I first begin a painting session, I always wet the brushes I'm going to use first, then blot any excess water out on a paper towel. Never dip a dry brush into acrylic paint. The paint will dry VERY quickly on a dry brush and you will have trouble ever getting it out.
Second, I use a product from Golden
called Golden Open Gel Medium
. It's part of their line of Open Acrylic paints but you can use it with regular acrylics to slow drying time and help with blending. I work a bit of this gel medium into my brushes and wipe out any excess. That will also help to keep your brushes from drying out during the painting process. Since I wipe most of it out, just leaving enough in to help moisten the brush hairs, it doesn't effect the opacity of my paints unless I want to mix more of it into the paints.
There is another product similar to this made by Liquitex called, I believe, Slow Dry Medium. It will do the same thing.
I used to use one of the brush holders with a coiled spring that holds the brush handles and suspends the head of the brush in water while not in use, however I found that this allows too much water to begin soaking into the glue inside the ferrule and caused my wooden brush handles to crack because the wood would get waterlogged, as well. Since I made up my little brush/sponge tray, this is not a problem. The brush won't become waterlogged from sitting on the wet sponge.
Hope that helps.