I bought a set of refillable bingo bottles from Discount School Supply. I bought these a couple of months ago and we love them! I filled them with tempera paint. I had to water it down a little because the paint was too thick to work well. My kids love these, they paint really smooth lines and also make perfect dots. I love them because they are relatively clean and the kids can paint without making a mess. No water, no paintbrushes, no spills, perfect! I also love that they are refillable. The kids can get the lids off to paint, but then there are caps underneath that have the sponges that the paint comes through, and those fit tightly enough that there is no way the kids can get them off. This is a great activity to keep the kids busy while I’m making dinner, or if I need a few minutes to finish something that I’m working on.