I joined a monthly quilt block club. They send me four different fabrics each month and I have to make a 12 1/2 inch block from these four fabrics. Rules are: use all four fabrics and block needs to be 12 1/2 inch.There are 12 people in this club and each month a different person picks four fabrics and everyone makes a block.Then you receive 12 blocks once a year. The cost for each player is $5.00 a month.My mom did it last year she really enjoyed it .

I'm assuming your 12.5 block request is 12 inch finished as these are.:)

http://quilterscache.com/BlocksbySizeC.html

Quiters Cache is one of the best sites :D You can go straight to the size blocks that you need :D:D:D

Also, check the BOM here on the board, many of them have been 12" blocks too :D:D:D

sounds like fun

Sounds like a lot of fun. I'll be watching for more to come on this one.

This is the site I was going to suggest. It is wonderful. I got my block from here for our quilt clubs 12 1/2"block mystery quilt.