All products on the Onetile website are exclusively first class.
The term
first class refers to imperfection-free ceramic products covered by the manufacturer's guarantee in the event that the supplied product is affected by apparent or hidden defects. In the case of
first-class tiles, some minor aesthetic defects are admissible on a limited number of tiles (no more than 5%, i.e. 5 tiles out of 100).
You can find more information in
this article, in the section
"How to recognise quality porcelain stoneware".