Store small amounts of unused acrylic paint in film cartridges containers. Dab the color on the lid if the container is opaque. Wal Mart gave me as many as I wanted... free!
Tip from: Ken Ralls.
I use my palette knife to place a dab of the paint on the lid so I may remember the colour inside or alternately use a permanent marker to label them. That way, you are not needlessly opening and closing the containers and letting in air which will dry out the paint more rapidly.
The little containers hold the moisture in the paint for quite a while. Sometimes, I even paint right out of the film containers without even placing them on a palette at all.
Tip from: Doris H David.
I use acrylics in painting my bird wood carvings. To save smaller quantities of mixed paints, I use plastic film containers and for larger quantities I use baby-food jars. In both instances the mixed paints keep for several weeks before drying out. Just put the word out with your friends that you are looking for either type of container and it's remarkable how quickly you acquire a reserve of spare containers.
Tip from: Hans J. Schneider
Being a student, I'm on a very tight budget, and can't afford the fancy stuff like stay-wet palettes. But when I'm working on a painting, I keep my colours in an (styrofoam) egg-carton. It's great for holding plenty of paint, and for mixing as well. If I stop in the middle of the painting, I lay wet paper towel over the paint and close the lid up. The paint stays moist for about three days!
Tip from: VenusWillow.

