They are durable and strong! I bought two of the largest coasters and a 16 inch coaster that fits my glass topped desk. My calculations were wrong by about 1 inch. They got really close to the edge of my desk and one day they fell on my glass table with my Apple monitors on it and didn't break. I was shocked. But the thing is, the abstracts are great and look great. Swipe to see closeups, before and after!