clear plastic sheets for whiteboard?

i’m looking for some clear plastic sheets (similar to laminating) that i can use a dry erase markers on and place over the whiteboard in my classroom – for putting music notes on the staff etc.

i don’t want to rewrite them over and over. since there is no laminator in my school, i am at a loss for what to use. of course i can by laminating rolls. anything else i can use and where to get it?