Shirt *Construction* techniques

[Gerry]

I'm actually more intrigued by their use of pallet strapping as an edge stitching guide.

It's mainly used to provide traction for the feed-dogs. You'll note that they use a compensating foot for the edge stitching. Because of the gapped 'step' to the left of such feet, there's not much for the dogs to push against when fabric is thin, hence the use of a strip. Strips are also useful when commencing sewing from the edge/start of seams (no need to begin a little further down, then back-tack). Again, they provide traction: something for the back of the dogs to push against, in this scenario. But, as you mentioned, they can also act as a guide. Pretty useful things all-round.

Things are less problematic with industrial machines, but I have a compensating foot for my old Singer and it's very temperamental unless I use pallet strapping for at least part of a run - there's a lot of 'jogging on the spot' by the needle, otherwise, and/or skipped stitches when layers are thicker (the strapping helps to compress them). I found a long strip of the stuff in a neighbour's recycling bin while out for a walk, gave it a bleach to clean it (just in case) and was good to go.