One note on the tute at feeddogsdown is that you might want to use a light weight interfacing on the fabric before you cut it. I made these in a little workshop at our LQS and the owner and her elves had worked with batting; heavy interface and finally hit the sweet spot with the light weight interface. Gives the placemat a little body but not so puffy that a stemmed glass will topple over.
they are a blast - we never know what fabric we are going to see when the boys set the table!