the plastic should be plain without any writting at all.
You should be able to find acetate sheets at an office supplies shop.
Maybe at a hardware store or a building supply store. They may have some pieces, similar to plexiglass but thinner.
One that i bought before.
Hi: The Local hardware store sells Plexiglas Plastic sheet, However you could be use Poster-board or Cardboard for your templates instead of it ,It's cheaper and you use it to cut the stain glass better if you need it thicker than that, Then Layer it with identical pieces or use it to cut a thick piece of cardboard into the shape, Place it where you want it. Mark it with a felt tip marker. than you can start cutting it out where you want it and then use alcohol to clean the Felt tip marking's off ( use a wax marker to number the pieces) then start soldering or whatever to assemble it I hope this helps
