I have wondered this myself! I did notice that when I use a ton of starch my carpet does get a little rough or harder. I do have a steam cleaner though and I usually steam around that whole area about once a month. But that's probably because I May drink and spill coffee and crumbs and things around that whole area too. LOL. Hey! A girls gotta have coffee and snacks when ironing and quilting right?!?! That's part of the fun for me. Great snacks! HA!