Parchment paper is not like the old timey parchment people used to write on, it is a greaseproof paper that is used for baking. You could easily make your own greaseproof paper if you are sick of going to the store, use an old paper bag and some cooking oil. Cut open the paper bag, so it lays flat on your baking tray, add a tablespoon of olive oil and spread it over quickly with a pastry brush, make sure the paper absorbs all the oil. Store it and let it sit, and you can use that as a baking base. The oil will do the job as it is no longer a dry surface. However, we still think that it is just so much easier to just grease/ oil your baking trays.