I don't always think it is us who is off in our work. I recently made a quilt where triangles pieced into squares were used as part of the design and the blocks when pieced were a full inch too small to match up to the plain blocks that went on each side of them. There were numerous errors in the fabric yardage needed also. I sent a note to the quilt designer and much later got a note back saying the corrections had been made on the fabric website (free fabric mfg. pattern). Well they corrected the yardage amounts but never did a thing about the pattern being incorrect. I had to re-draft the triangles/squares and some other pieces as the quilt went along. I also had to end up buying almost twice as much fabric as the pattern stated was needed, mostly because I had to re-cut so many pieces that were incorrect. Never again will I use a free Mfg. pattern!