[QUOTE=bigsister63;5767553]
Originally Posted by
Sucia
I think you forgot to figure in the seam allowance for the center of the block. For a 5" block you need to start with a 5 7/8" square. Then cut on the diagonal. When the pieces are sewn together, they will measure 5 1/2" and when they are set in the block they will measure 5" square."
Correct! IMH you should cut the squares 4 7/8", Draw a line diaginally on the square, sew 1/4" on each side of the line and cut between the stitching . This will give you a 4 1/2" square or 4" finished. Even if you decide not to do 1/2sq triangles the largest size block you will get is 4 1/2 due to seam allowance.
OK. I am assuming here that you are not going to use any of the 5" squares to make the HSTs. You have (at least) 2 other fabrics that you are working with. Is this correct?
If this is the case, bigsister63 is partially correct. The squares already cut are 5". They will finish at 4.5", so that's the size you use in the calculation. So now I'm going to give you another number!
You add 7/8" to the FINISHED size to get the dimension to cut the starting squares.
So, 4 1/2 + 7/8 = 5 3/8. Since we are not big on eighths, round up.
Cut the squares 5.5 inches. Draw a diagonal line, corner to corner on the back of one square. Place this, right side together with your other color. Sew a scant 1/4 seam on each side of the line. Cut on the line. Press. Trim resultant square to 5".
If I have not understood you correctly, and you are going to use the 5" squares to make the HST, then, after sewing, you would trim to 4.5" and they would finish at 4".