Small clips made of two bars, which spread open to hold sheets of paper or cardboard.
paper clips
Small clips made from a piece of bent metal wire; they are used to hold a few sheets of paper or index cards.
clip
Device with two articulated arms that are pressed together to hold such items as sheets of paper and index cards.
thumb tacks
Small tacks with short pointy ends; they are easily pushed in with the finger and are used to attach sheets of paper, cardboard or posters to a surface.