A matte is the cardboard material surrounding your photo, that is then placed inside of a frame. You can get them at Xmas Tree Shops, Michaels, camera shops. I got the 11x14 size one, perfect for an 8x10 picture. I like white, the signatures show up very nicely. So you buy the matte, take the cellophane off of it, and bring it on board with you. You can either give it to guest services for the characters to sign (you'll get it back on Friday night of the cruise), or you can take it around by yourself and have it signed by whoever you want throughout the cruise. Very important tip here, have a photo direction (vertical or horizontal) in mind before asking for signatures, that way you'll know which way they should sign. As you get the professional pictures taken throughout your cruise, you can ask the photographer to take them any direction you want.