Threads Magazine recently published an article called 10 Better sewing Habits with tips from various sewists. Peggy Sagers said that the proper stitch length for construction seams- not basting- is 3.5mm.
Peggy’s reasoning is when tension is put on a garment, the threads will snap at 3.5mm. At 2.5mm the fabric will rip.
My sewing machine automatically starts sewing at 2.5mm. My basting stitch is programmed to be 3.5mm. I’m guessing that most people sew at 2.5mm too.
While I haven’t had time to test out these different stitch lengths, I have noticed that the fabric of my vents will sometimes tear right at the seam line.
In contrast, the tote bags I’ve bought haven’t ripped, even when weighed down with heavy glass bottles. The one seen above has a stitch length of a whopping 8mm. However, for the main seams of the bag the stitching was doubled up.
Any thoughts on this? At what stitch length do you sew? Any ex-industry workers out there who can tell us what the industry standard is?