I have six different beautiful purple batiks all 1/2 yard and plenty of white. I want to make the center a really pretty blue/purple batik. Not sure about block sizes but am thinking 10 1/2 by 10 1/2. I did my own calculations and came up with that size for blocks. Of course being new, I am probably so wrong. If I need more material (and probably do) that's no problem. Just need to know. I would like to make a full size.