Looks like parchment paper is the right word, or baking paper.
In English in the UK we call it grease proof or baking paper. I wouldn't use it personally, I prefer to use mount card, however the odd times I've mounted high gloss papers I've used silicon paper designed specifically for dry mounting.
When I got my press and without a release paper, I went to a local frame shop and bought a sheet off of a shop owner so I can get started. It's reusable for dozens of times. Since then, I bought a roll of it but still using the orignal sheet. It's expensive but you don't need much of it. I would suggest doing it the right material....
Baking paper worked, so then I can use it until I get the release paper. But I have to find something to put between the press and the paper, because the press made som marks through the paper. Maybe some mat board or something similar.
Don't know the english word, but is it okay to use "pizza paper" as releasepaper?
Release paper is coated with silicone. It's pricy, but it lasts forever, especially if you are just flattening prints.
Rather than buying a whole roll, you may be able to buy a couple of pieces from a local picture framer. One of the best things we did was get a wholesale account with a local framing supplier. You can get all of your finishing supplies at very low prices. In Georgia, a roll of the release paper is about $60 wholesale.
EDIT: Classic case of not reading the rest of the thread before replying!
Right. It is common to use two pieces of mat board and put the print between it. I also use release paper between the emulsion side of the print and the mat board. Otherwise, I risk getting the texture of the mat board on the print.
Be sure to keep these mat boards clean. Any particles caught in it will leave marks on the print.