Years ago we made cards with Elmer's glue, black construction paper, and chalk. You take black construction paper and drizzle the glue in a design on the paper. Make sure you leave open space between the drizzles.
After the glue is completely dry it is transparent. You can color in the sections between the glue with colored chalk. It looks kind of like a stained glass window. This can make good handmade Christmas or gift cards. It's also a fun craft for children. They look very nice.