Properties of Porcelain
Like Mary Poppins, porcelain is practically perfect in every way! At Pental, we have a penchant for pretty patterned porcelain whose primary purpose is to perfectly punctuate your project! Ok, enough with the p-words. Seriously though, we carry over 40 series of porcelain tile in a vast array of colors, shapes, and sizes. We thought it would be a good idea to dedicate today’s blog post to porcelain and its properties!
A quick recap from our Ceramic vs. Porcelain blog post reminds us that porcelain is made primarily from clay and feldspar that is fired in a kiln at a very high temperature. This makes an extremely dense material that is nearly impervious and is resistant to acids, heat, scratching, and UV rays.
Porcelain tiles have the same composition throughout, which is called ‘full body’ or ‘through body’, and which means they can be either glazed or unglazed. Glazed porcelain tiles are pressed and then glaze is applied only to the surface before being fired in a kiln. These tiles can have a design that varies in color or pattern and can be a gloss or matte finish.
Sometimes a manufacturer will add pigments to the porcelain mixture prior to pressing so the body of the tile will match the color of the glaze to be applied later. This is called ‘glazed through body’ or ‘color body’ and provides an advantage in that if the glazed surface is chipped or worn, damage is largely unnoticeable due to the colors of the tile body and surface closely resembling each other. Even so, having a chipped tile is very rare because porcelain is so durable. Another main advantage of color body tile is aesthetic, in that the edges match. Thus, if you have a countertop or wall where the tile edges are exposed, you won’t see a different color line.
In addition to glaze, there are a few other methods of embellishing porcelain tile including a process called ‘double loading’, as well as digital inkjet printing. The ‘double loading’ process, also called ‘double pressed’, uses a second coating of very fine colored powders applied to the tile’s surface, pressed to the base under high pressure, then kiln fired. The top layer is approximately 1mm thick and is comprised of porcelain clay infused with various color pigments that create an infinite range of possible color combinations.
Digital inkjet technology provides even greater capabilities in terms of the finished product. Printing in this way allows for the consistent transfer of graphics and patterns in a superior resolution. Hi-res graphic images can be printed onto porcelain tiles of any size, shape, or texture, including uneven or irregular surfaces. Images can also be altered to change or enhance the look of the original graphic.
For tiles that are pressed, and not rectified, there can be slight variation in size or ‘caliber’ between batches. Because of this, we recommend a minimum grout joint of 1/8”, up to 3/16”. In order to create a more seamless installation, many tiles come in a ‘rectified’ format meaning the tiles are re-cut by a machine that makes each tile exactly the same size. In this case, the sides of the tile are shaved and calibrated to allow for installation with a very narrow grout joint (1/16”) that could not normally be achieved with non-rectified tiles. Some people mistakenly believe that rectified tiles can be butted together with no grout joint, however this is not recommended because most floors have imperfections that require at least a minor grout joint to allow for expansion and contraction.
You can check out all of our porcelain tile series here. Happy porcelain picking!