The one that is thicker than sliding folders. And in different colors.
Maybe in a school supplies store or National Book Store
This Site Might Help You. RE: Where can I buy polypropylene plastic sheets here in Cebu, Philippines? The one that is thicker than sliding folders. And in different colors.
Go to a hardware store and buy a Painters plastic drop sheet. They are about 3 x 3 meters so quite big but only cost a few pesos. Painters use them when painting the inside of a house to cover furniture and just throw them away when the job is done. You can buy one and cut it up to any size you want , cheap and a good size. You will gets a lot more sheets doing that than buying them separately. It's just an idea for you but hope that may help you out.