a number of years ago people also said silk thread would cut your fibers & should not be used---those are myths & who knows where those *thoughts* come from...polyester thread will not damage your 'fibers' and is used a lot in the quilting/sewing world. polyester is a good strong thread, color fast, does not shrink and often is the choice of many long-arm quilters because many cotton threads are not able to stand up to the high speed machine. polyester is lint free (cotton thread can create a HUGE amount of lint) so, if the thread is the right color, weight, and you want to use it- go right ahead. also, visit the website for Superior Threads- there you can find *free* charts you can print off that tells you about all the different kinds of threads- what they are best used for- and what needles to use with them...it's a great resource.