We like to keep Skittles in our canisters. Sometimes we mix it up a bit and go with M&Ms. Seals are included with each canister to help keep your goodies air tight.
We recommend that you do not display unglazed canisters with the silicon seals, but rather present a painted sample. The silicon material can rub against the bisque, creating a barrier, which can prevent the paint/glaze from properly adhering to the piece.