1. To make your printing plate (beige rectangle in the middle of the photo of supplies) prepare 2 boxes of unflavored Knox gelatin following the instructions on the box. I used a 9x12 cake pan as the mold. After the gelatin becomes hard in the refrigerator you will be able to cut it into slabs, just like brownies, in the size that you would like your prints to be.
2. You can use either acrylic paints or water soluble ink and apply it to the surface of the gelatin slab with a brayer or a brush.
3. Place stencils, doilies, leaves, string, flowers....on top of the gelatin plate.
4. Gently press a sheet of paper on top of the plate.
5. Apply a different color to the gelatin plate along with other objects and print again on the same print.
This process requires a little trial and error and some unexpected results. When I did this printing project with a group of four year olds I gave them a whole stack of paper to work with and told them that some of their results would be disappointing, but that that was part of the process. By using more than one color you can achieve some interesting overlays. The gelatin plates can be washed and stored in the refrigerator for at least a week.