I finally got up the nerve to make OBW and's actually found it to be surprisingly easy...I love it. As Forest Gump said about life....OBW's are like a box of chocolate, you never know what you're gonna get. But, now to my problem....a couple of my blocks think they are skull caps...all puffed up in the center where the corners all meet. I took them apart and re-sewed them...same result. The triangles are the same as all the others and the seams are all 1/4" in width. What did I do?

It sounds like they stretch a little.

did you sew three together and another three, and then sew those into a block? that helps a lot. and actually if you are doing a whole quilt of these, laying them out in rows and only sewing the top half of a row together and then the lower part together into a row and then sewing those rows together is so much easier. No Y seams that way either.

The bias edges got stretched, and that is what makes them "D-Cups".

You have to be VERY careful not not stretch the edges, just let the feed-dogs pull them through. You have to be careful when you cut, plus you have to be very consistent about your 1/4 inch seams. I always sew from the outer edge toward the inner tip. I don't know if that helps, but I've never had anything but flat hexs, and I've done a bunch of OBW's.

You can tell if your seams are correct when you get 3 triangles sewn (a half-hex). If the edge is straight, you've sewn correctly. If it bows, your seams are not consistent.

Keep practicing and you'll get it. Good luck and let us see the finished product.

Triangles have bias edges which have to be treated very carefully. Sounds like they got stretched. At this point, I would see if taking a slightly larger seam where the 2 halves of the problem hexagons are joined will make them lay flat. Just pin or baste one to see if this helps. Mine had one or two that were puffed up a bit, but it all quilted out.

if you cut them from strips one edge will not be bias and that edge should be on the outside.

Thanks for posting this...will be very useful for those of us who have a OBW in the works.

Oh and I hope you get your little glitch sorted.

starch! Its you best friend with bias edges.

Also, do NOT prewash your fabric.

Maybe make kufis or kippehs?