Our guild does a lottery block of the month. You use your own fabric and you get to keep the block. The pattern is picked out of a book by participating members. This year we are using the book "Around the Block". Last time we did it we used "Block Tool". The book used depends upon what the members want to use. It is a good idea to use a format that offers different size blocks for the same pattern. Some of us are doing 12.5 inch blocks and some are doing 9". I am doing 4" and 6" blocks.