yourATCstore Halloween Spooks, The Raven & More Collage Sheet. This Halloween Collage Sheet features 3 spooky 2 1/2 in. 3 1/2 in. Artist Trading cards, 12 words and phrases and enough other images to create your own Halloween ATCs. This matte finish collage sheet is professionally printed and comes in a crystal clear bag for protection. Each collage sheet measures 8 1/2" X 11" and is acid free.