Polyester quilting thread is a man-made thread that works well with man-made fabrics which often have stretch qualities in the fabric. Polyester is sold in three basic types: spun polyester, filament, and trilobal thread. Spun polyester most resembles cotton thread and is a good general use thread. Shorter polyester fibers are spun together and twisted to create a thread which looks very much like cotton thread only with greater strength, durability, and color fastness. Polyester filament thread is a single filament or several filament twisted together to form a multi-filament strand. Most polyester filament thread is made into multi-filament strands to create a thicker thread. The benefits of using multi-filament thread is that there is considerably less lint and thus less cleaning of the sewing machines. Trilobal thread is a fairly new invention. The trilobal polyester fibers are triangular and reflect more light, giving it a sheen which the multi-filament previously lacked. Now the trilobal polyester can more easily compete with high luster threads like rayon and silk threads.
Polyester thread can be used for quilting without fear of the polyester thread tearing the quilt. It is best to use cotton thread to piece cotton together in a quilt, but any thread can be used to create the quilting stitches. The most important thing to watch for is compatibility. A thread that is too thick or forces the use of too large a needle and leaves big holes when stitched is not a good choice. Choose a thread that will allow you to create a tastefully created finished product. Polyester not only has several constructions, it also comes in a variety of thicknesses. Sizes 15 to 23 is used for sewing average weight fabrics and require a size 10 to 12 machine needle for sewing. Size 33 and 46 are also used for general sewing. The machine’s needle size can go up to a size 16 for these threads. A size 16 needle is very large and may not be appropriate for quilting, but works fine for sewing denims and heavy weight twills.
Polyester is very strong, stronger than rayon thread. It is heat resistant and withstands heat up to 510 degrees. It is also resistant to strong cleaning chemicals and will not readily break down when exposed to chlorine, sunlight, mildew, and abrasion. Polyester is also colorfast and does not lose its strength when it gets wet. Polyester is easier to use at higher machine speeds because it doesn’t break as easily. When choosing thread, choose polyester if its durability, strength, and look will serve your purposes and keep in mind the additional benefits polyester thread provides like colorfastness and resistance to mildew.