I’m so disappointed in these mats. We’re on our third one in barely 2 years. I LOVE the thickness and the nontoxic material but they just don’t last. I replaced our first one after about 9 months due to extreme yellowing of the white side and our replacement did the same thing after the same time frame. I made sure to follow cleaning recommendations throughout ownership. Our dog medium dog (50 lbs) isn’t allowed on the mat because his nails puncture it. This is q side by side comparison of our 1 year old mat and our brand new mat. You can see that my gentle cleaner (water, vinegar, and a drop of Dishsoap) has soaked into those prior punctures from our dog and discolored the surrounding area even more. It is a stark difference in “whiteness” between the mats overall. The company did send a replacement (our third mat in total) which was nice but even after reaching out to them many times over the last couple years on cleaning tips, they’ve remained unable to provide substantial support in this area. When this one starts to yellow, I will be looking at a different brand.