the problem is that you cut them all out.... look up 'magic squares' on youtube and see how to sew triangles together without having that bias edge to contend with, which is the trouble maker... when i start a quilt now, i locate each of the HSTs in each block, define which colors go together, multiply by the total number of blocks for each color combo and get to work...i make all the HSTs first... and all the triangles are taken care of in that step...each of your diamonds is really 2 HSTs and if you construct them that way, all will be flat and all will go together easier...
you mentioned sewing 4 tog and then the other 4 and setting the two halves together last...this is right, but did you sew 1 to 2, then 3 to 4, and then 2 to 3? or did you sew 1 to 2 to 3 to 4....because....if you did it the second example... they will not lay flat... sew in twos all the way round, then join into 4s...then into an 8... but still the HSTs instead of diamonds will be easier to handle. And be sure when you get all 8 points joined in the center, to turn it wrong side up and pick all the sts out of the seam allowance....it will make the little interior 'flower' that lets the outside lay flatter...
Last edited by deemail; 12-31-2011 at 01:35 AM.