This was an experiment for me. I believe Betsy showed this technique on a MIM a long time ago and I've just never posted the card I made. I used Mehndi Medallion as the background and the limited edition Round and Round stamp set.
Once you stamp the background, you take some regular tissue paper (like you'd find in the gift wrap aisle), ball it up with lots of crinkles, then smooth it back out. Put glue all over the front of your card - don't miss a spot. You'll need a wet glue for this - no glue tapes. Then simply lay the tissue paper on top. When it's dry, trim the edges.