Vihara tile is perfectly imperfect.  Surface folds and shallow cracks are to be expected with this handcrafted product.  They are a surface feature that is present before installation and do not affect the integrity of the tile.  Be aware that the handmade surface of Vihara glass tile will collect grout during the grouting process. The amount of grout “visible” after installation will depend primarily on the contrast between the grout color and tile color, how well the tiles were cleaned before/after grouting, and viewing distance.
BEFORE installing, the installer should carefully read the installation instructions.