Artist Trading Cards are a whole new "movement" in the art world. The idea is to create original miniature works of art- and then swap trade and collect Art Cards by your friends and other artists. Artist Trading Cards are available for just about every media; both wet and dry. There are even envelopes to hold your finished cards. Strathmore Watercolor Artist Trading Cards are heavy duty acid free cold pressed watercolor paper. There are 10 140lb sheets per pack. They measure 2-1/2 x 3-1/2 inches. The sheets are not bound; they come in a plastic resealable packet.