These sre obtained with unpolished tiles as from the frame, or polished or treated with an
oxyhdrogen flame thus leaving the surface in a state of roughness thet is almost natural
but far more precise. The adges are milled and the thickness is almost always 2 cm. Widths
may be from 15 to 40 cm; lengths as desired or of a fixed size. With the same technique,
socles and skirting-boards can be made with a minimum thickness of 1 cm and the lengths
as desired or fixed.