Monday, March 25, 2013
How to Mattress Stitch (Why Seams Don't Match Up)
I've had many knitters ask me why when they mattress stitch their seams there is never a perfect match. There are a several things going wrong when the seams don't match up.
The first reason has to do with the problem that instructions for seaming often don't mention the one row shift created by the seaming yarn. To compensate for that, seam in this way. With the right side of the knitting facing you, use your threaded needle to pick up one bar between first two stitches on one garment section, then the corresponding bar plus the bar above it on the second garment section. After this you can cross back and forth picking up two bars on each side to align your pieces. If you want to get really good at this, practice on samples made with two row stripes.
I like to use the yarn tails to join at the top and bottom edge. I use my needle and imitate the cast on and cast off stitch path across the two pieces to make that edge appear to be continuous.
Another discrepancy is created by casting off at the beginning of right side and wrong side rows. That means the right front (armhole cast off on wrong side) is seamed to the back (armhole cast off on right side). There will always be a one row difference here. I normally ease this in slightly at the top of the armhole, where it can be best hidden.
The third reason they don't match is because knitters use measurements to determine length. If you use rows or pattern repeats and keep notes on which row of a pattern repeat you worked the cast off on you are much more likely to be accurate. Measuring is notoriously inaccurate. As a test, on your next garment, try measuring on both sides of the back. Many knitters will find that the left side will measure a little longer as many of us loosen up a little on the purl side of stocking stitch.
Final tips. Knit your sleeves and garment fronts at the same time to be sure they end up the same length. Make notes on your pattern to detail which row of the stitch pattern you begin armhole and shoulder decreases when working visible patterns.