At the place I worked, they just used a "small" size baking paper which was the same stuff we used to cook the small pizza's on in the oven. It's referred to as a lot of things, "baking paper", "Parchment baking paper", "siliconized baking paper" yada yada.
I don't know if those are all the same, but I am sure there are a few varieties, coated or not. I would personally stay away from anything waxed. Even if it is microwave safe.