I Spy Blocks are blocks that we make children's blankets out of where you can say I Spy Something ..... and the child finds it on the blanket. In this month's case, the theme is pink ... as long as there is pink in the blanket then most any colored/designed block will do. You cut out 40 each of 3 different materials and send them to me along with a Self Addressed Stamped Envelope for me to send you your blocks in return. You never know what you are going to get in return. I got 120 different blocks back from the I Spy I did before I took over running them.