Paint cans in my garage tend to reproduce and grow. Pretty quickly after various projects there is a collection of 1 gallon paint cans taking up huge amounts of space. When my wife and I went to finish painting a room, we discovered our less than half filled paint cans also thickened a little over time.
To put and end to this, I purchased a few 1 quart cans from the paint store for $1.88 a piece and poured the paint out of the gallon containers into these little guys. In the end, I wound up throwing away a very small amount of paint, but a very large amount of paint containers.
He added the following tip:
Paint in its liquid form is hazardous waste, however, as a solid it is safe to throw away. I combined all my left over paint into a single one gallon container, capped it, and saved it with the used lightbulbs for hazardous waste disposal. The rest of the [empty 1 gallon] cans were left outside in the sunlight to dry, then they were simply tossed.
Thank you, Mike, for the great tip!