The caliberrepresents the exact size of the tiles.
Ceramic tiles are manufactured at high temperatures. ( /- 900 to 1,300 degrees). Before the tiles go into the oven to bake, they are several inches larger than afterwards. During the process of baking, the tiles shrink a few centimetres. Exactly how much cannot be predicted in advance and depends on many factors. As a result, tiles coming out of the kiln may vary in size. These are normally not centimeters, but rather a fraction of millimeters to a few millimeters. To achieve a correct floor result, we recommend not combining tiles of different calibers or choosing rectified tiles. Rectified tiles may also have a caliber. However, within one batch, the caliber will be more dimensional than for non-rectified tiles.