I started off with the other plaque that had been painted using crackle medium. Then came the saying that I found online which was perfect for a key that I had picked up as an impulse buy at Michaels a long time ago.
I coated the entire plaque with mod podge and then laid down the piece of burlap. To keep the burlap from fraying I covered the top of it with more mod podge. I had intended to hot glue the key down after everything had dried but in the mean time I had just laid the key down to see how I liked it. Later when I went back to glue the key on I discovered that it did the job itself. The mod podge surprisingly created a pretty strong bond.