Why can't a large piece of fabric be used with strips of freezer paper on the front, to make each 'block'. That way the guests can see what others have written. DO put freezer paper on the back to make it all stable. Make enough of the large pieces, so small blocks will not get 'lost' in the shuffle of the event. You could write a sample block, in each of the larger pieces, to show what you would like others to write.