140lb. watercolor paper
Cut the watercolor paper into 1.5 inch square pieces. Cut letters out of the squares using a hole punch for the inner parts of the letters. Trim a piece of watercolor paper the same size as the plastic pieces. Stack everything together; plastic "A" first, then fun foam, watercolor paper then paper letters and finally, plastic "B". Line the foam and paper up at the far end of the plastics. Run the sandwich through the press, front end first. Without the 1/2" of fun foam, the front of the sandwich is thinner and will "catch" when going through the press.
I used large scissors for a primitive look but you can use smaller ones for more detail.
Cut shapes or use punches instead of letters.
I like to use cold press watercolor paper as it has a texture. The embossed parts become smooth, contrasting with the rest of the paper.