Have you worked with porcelain and stone tiles? If so what problems have you encountered?
If they do not bring up the subject of the variance in material size and thickness, you can be assured of problems.
Tile sizes may vary from box to box, color to color or manufacturer to manufacturer; not to mention bevels and their lack of consistency from tile to tile. In general, most inconsistencies are made up for by using grout lines. However, even minor inconsistencies can create difficulties for an inexperienced waterjet company, thus affecting design integrity.
For a visual understanding of the importance of knowledge about stone please view our gallery.