Well which is it?
I was searching for difference from spun poly thread to other types of poly thread. Any thread experts here?
Tensile Strength: Spun polyester sewing thread, with its twisted short staple fibers, exhibits higher tensile strength compared to regular polyester thread made of continuous filaments. This superior strength allows spun polyester thread to withstand greater stress and strain without breaking.
Spun polyester threads are made by spinning or twisting together shorter lengths of polyester fibers. This is similar to the way cotton threads are made. These short fibers are then twisted together to produce a thread of the desired size. Spun polyester threads give the look of a cotton thread, but have more elasticity. Spun polyester is economical to produce and is usually a low-cost thread. We don't recommend spun polyester for quilting, as it is not as strong as corespun, filament, or trilobal polyester threads.