Select your poster size: 16" X 20" OR 18" X 24". Then select your paper type: Glossy Paper Posters are printed on a Photo Quality, glossy paper stock.They are delicate and not scuff resistant or waterproof. 12pt C2S Blockout Posters are an economical paper option featuring thickness and durability. Its semi-gloss surface and the block-out center layer will keep the light out, ensuring 100% opacity.