I did this for neice's wedding quilt. Used the pigma pens and backed the squares with freezer paper. But I used a Manila file folder, cut a hole the size of the finished blocks, marked the inside with pieces of masking tape the size of unfinished blocks. Slip the block into the folder, close it, hand to guest to sign. They have a visual that they will understand and no over lap to worry about. We used the blocks instead of a guest book, so had two folders going at the same time. Worked pretty slick.