Those are nice blocks!
My fabric is cut and ready to go, just need to get to town to get the right change for return mailing. I plan on sending enough for both mailings at the same time. DH and I rarely use cash, and though we both keep some "just in case" it's normally in larger denominations than what I need for this. DH will get change the next time he's in town for something, so I should be ready to mail this weekend.
I'm sending assorted tonal solids - no duplicates - with instructions to use prints, but no neutrals (no blacks, whites, creams/beiges or greys). I want the patterns to be due to different colors/patterns, and not the typical "light/dark"that we think of.
I'll post some pictures of what I'm thinking to help give a better idea of the concept. Though you are free to do something else if you prefer.