You can find unfinished trays in various sizes at the craft store. They go on sale regularly, so watch the ads. You can decorate or paint the tray in whatever finish you want, then glue the corks down in the center.
Try using embroidery hoops. They come in several sizes, so that gives you a lot of choice. Some are even small enough to use for coasters. I'm guessing you intend to cut the cork down and then glue them into 'frame' to make hot pads. A bonus is that you can usually get embroidery hoops at second hand stores for 50 cents or less AND you can paint them cheaply for variation. Good luck. Dianne
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