If I don't want crinkly I wash my batting in hot water and dry in hot dryer. I also prewash my fabric in hot water and use hot dryer. I can then wash it after I'm finished and press it without any crinkles. I don't know if cotton thread shrinks that much to make a difference but I use poly to piece and quilt if I don't want any crinkles. Using Minky is an iffy for washing and getting flat and smooth.