Now that I'm studying tailoring, I've noticed things I hadn't even looked at before, like how some stitches seem to squeeze the fabric, particularly on knits. It got me thinking, and that lead me to a question that sounds a little stupid; do thread manufacturers shrink the thread before shipping it?
So, follow me on this; you pre-shrink fabric because you know it will shrink when it's washed but, if the thread isn't pre-shrunk, wouldn't it shrink and cause the thread tension to tighten? That said, how the hell can someone pre-shrink thread? 🤨🤔
Alright fellas, as you're the experts, I'll take your word for it but, I don't believe it. 🤣🤪
I'm sure you're right about the polyester thread, where heat is concerned. I never wore a leasure suit in the seventies, but I heard you didn't want to be wearing one when the room catches fire. 😲
I qualify my contrary opinion by thinking about the Lapel Roll discussion; if the length of stitches gives fabric structure, then the fabric gives the thread structure as well. If then, you use thread that doesn't shrink to sew fabric that does, the result would be a change in the original seam characteristics, since the fabric would have slid along the stitch thread. I'm guessing this would be more pronounced if the thread was smooth.
I might say the only way to make sure the fabric doesn't shift along the stitches is if the thread was exactly the same as the fabric. Even if you pulled a thread out of the fabric itself and used it to sew a garment together, the act of weaving the thread in and out of the fabric would change the dynamic of the thread and fabric, making it behave differently than the surrounding fabric untouched by the invading thread.
I'll let you know if I try a little experiment.🫣 I'm thinking I'll get some different threads, measure them, wash, dry, and measure again. The next experiment would be to use the same variety of threads, stitch some fabric together, and run them through the wash as well.
Lastly, since I'm neck deep in my morning wonderings; 🤔 Are threads spun or woven in as many varieties as rope? If so, flexibility of the thread would be determined by the twist or weave ov the thread, not simply the quality or blend.
Now that's some serious overthinking for you, and I've only had one cup of coffee 🤣
Gerry is right.
I'll add: cotton thread shrinks more than polyester, due to the nature of its fibres and water absorbancy.
Polyester or nylon thread however can shrink due to heat. In fact, Waxed silamide tends to shrink when exposed to heat instead of water.
But as Gerry mentioned, quality thread such as Coats, Gütermann, Amann etc will not give you that trouble in standard production methods. Especially sewing maching threads.
Reza
International School of Tailoring
Yarns are held in tension on a loom and they remain in that state once the cloth is woven (almost like a knotting effect). Most of the shrinkage in cloth results from this tension relaxing upon contact with water/steam.
However, shrinkage can also occur in individual yarns. The weight of water/dye/bleach can stretch yarn during its processing. If dried quickly, that stretch is 'set' and only when wetted again does the thread revert to its natural state.
Thread, particularly if cheap, can shrink, but quality stuff tends to be mercerised, which is less prone to this problem. Especially if manufactured by a brand name.