I recently had a comment on my quilting Facebook page about an error in a pattern, but the pattern is correct. Let's talk about the problem the quilter encountered, because I suspect it happens to many beginners.
The pattern asks quilters to sew five 2" wide strips of fabric side by side and press. After that, one end of the strip set (the long patchwork unit that was just created) is squared up. Starting from the squared up end, the instructions say to cut as many 8-inch segments from the strip set as possible to create 8" squares.
The quilter was unhappy with the 8" length, stating that it was a waste of fabric because the segments should be 7-1/2" long. Let's examine why 8" is indeed the correct length.
- Each of the inner three 2" strips has a quarter inch seam along both sides, making those strips each 1-1/2" wide in the completed strip set.
- Each of the two outer strips has a seam along only an inner edge, making those strips 1-3/4" wide.
- 1-1/2" x 3 = 4-1/2" in width, and 1-3/4" x 2 = 3-1/2" in width (the slight differences in width are visible in the photo above, although the strip sets are from a different pattern).
- Add 4-1/2" to 3-1/2" and you'll get 8", the length to cut a segment -- and the width of the strip set.
Why did the quilter's segments only measure 7-1/2" across? A few possibilities:
- Seams may have been wider than 1/4", 'eating' some of the strip width.
- Pressing may not have been adequate.
- Strips might have been slightly narrower than 2".
- A combination of errors could have occurred.
Even small discrepancies are compounded when several seams are present in a piece of patchwork. It's very important to set up your sewing machine to sew an accurate 1/4" seam allowance, to press carefully but thoroughly, and to take care when cutting strips of fabric. Measure as you go to make sure that your patchwork's dimensions are correct, and always make sample blocks before cutting all of the fabric for a quilt, because all pattern designers (including me) do make mistakes sometimes.