I made this 3D pinwheel and I think it needs more. So I want to put a border of regular pinwheels around it. How do I determine how big the pinwheel squares should be so that it fits all the way around?

It would depend on how wide you want your border. Try half the size of your 3D blocks and measure the total length of quilts. Try a square of paper that size and fit it along the quilt. If you have 8 inch blocks and 2 inch borders, then you would need 8 four inch blocks on the side to make a four inch border all around. Just guessing at the size from the look of the picture. it is a lovely quilt.

Ph if my guess is right on the sizes, you would need ten down a side including the corners, and if it is square, that would mean, thirty six total, if I'm counting right in my head in the middle of the night. Happy fourth!

Won't attempt to answer your question but the quilt is lovely!

I'm with homespum, but the quilt top is beautiful

I love it, the colors are beautiful. I am so going to have to learn the 3-D pinwheel technique.

Love your pinwheels but can't answer your question.

Beautiful colors and workmanship. Show again after the border, please. It is lovely.