I am often asked if I use polyester ties and/or mix them with silk ties.  The answer is yes, I do, but with caution.  There are some lovely polyester ties out there (many of my printed Christmas ties are polyester), and it would be a shame to pass all of them by.  If you use them, remember to use a cooler iron for pressing and/or a press cloth, especially if mixing with silk.  Silk tolerates a higher heat, but never use a direct heat higher than what your most sensitive fabric can tolerate.