I bought these mats to cover my hardwood floors while my baby was crawling and learning how to walk. They smell so much that I just left them in the open box to air out for a few weeks. That didn't do the trick though. I had to wipe them all down with soap and water since my baby would be all over them and that did get rid of the smell. These mats do not take their shape back after something has made a dent or mark in them. The alphabet playmat that I have takes back their shape, so I guess the material of these mats aren't as good in quality.