I loosely followed the instructions in Teaching Montessori in the Home: The Pre-School Years
to make these. Kansas Dad and I were at a superstore and I picked up oodles of the paint cards from the home improvement section. I had come prepared with a list so I knew how many of each card I'd need. At home, I trimmed them so only one color was showing and glued them (with a glue stick) to roughly square pieces of poster board I had left-over from another project.
I placed them in plastic bags marked as Box 1, Box 2 and Box 3. I wrote the "box" numbers on the back of each card so it should be easy to sort them again if the kids mix them up. (Ideally, only one set is out at a time, but I've seen how my children play.)
This project was a little more time consuming than most because I had to cut the poster board, cut all the colors and then glue them together. It is, however, something an older child could very easily complete entirely alone. It was also very inexpensive.
