My experience w/spray basting has been mostly good. I have always used cotton batting and Dritz (June Taylor too) basting spray form WM. I did use it w/poly batting once and it would not hold. I decided recently to try the 505 spray and it does not seem to hold as long or as tightly as the Dritz. I will be using some poly batting on two Christmas quilts so it will be interesting to see how the 505 does w/those.