First, you need some plain muslin cut 18" square. You'll need a coordinating backing fabric. Or you can be like me and just use some fabric that you had the most of. I think I had about 7 yards of the red and brown gingham. I love that fabric, I use it a lot. Now I'm going to have to buy more.
Materials. Plain muslin, a backing fabric, paint, paint brushes, masking tape, water and stencils.
Here's our set up. I taped the four corners of each kid's cloth to the table so it wouldn't move when they painted. You might want to use newspaper or something under it if you care at all about your table because the paint bled onto my table quite badly. Fortunately for me, I couldn't possibly care less about the looks of this table. In fact, I think the more paint and stains and nicks and scratches, the better.
I know, I know, gratuitous shots of my cute kids painting. So not fair.
I taped the lovely pieces of art to my window so the afternoon sun would help it dry. Then when it was dry I threw them in the dryer for a little while because I've been told that it helps set the paint. I don't know if that's true but it sounded good to me.
Pin the backing fabric and the painted front right sides together.
Trace a rounded edge if that's your pleasure.Iron the edges down. See all ironed; looks nice and flat.
Sew close to the edge all around the outside. I think I did about 1/8 inch.
The finished product. Use at will. I did wash and dry mine before I let them use the napkins.