These are really beautiful tiles and I love how they look installed.  They really elevated the room.  But I must say, the adhesive on the back is subpar.  I followed the instructions and used a roller but the majority of the tiles did not adhere at the sides and corners.  I pounded some of them down with a rubber mallet and even jumped up and down to get them to stick.  Others, kept popping back up, so I plan to pull some of them up and use a heavy spray adhesive to secure them.  Definitely a frustrating experience.