Can someone tear silver foil on Yom Tov to use to cover food?
We are not allowed to rip silver foil or saran wrap on Yom Tov, even if it in order to cover food. The reason for this is because it is fashioning the silver foil and making it usable to wrap the food, which would be makeh b’patish. Even though it is for food, this is not one of the melachos that are permitted to do for food preparation.
Bietza 32b, O:CH 508-1, 340-13.