Glazes come in a range of colors and textures. They are poured on a ceramic piece to seal and decorate it.
A glaze containscolorants and a ceramic material called frits or sand. It is a mixture that is melted in a kiln, quenched and ground to specific mesh size.
Engobe Tile Glazing
The engobe is a thin slip that sits between the body and glaze. It is generally applied before the glaze, often in a brush decoration style to enclose it. An engobe can mask the color of the tile body, hide surface imperfections (like those caused by iron impurities), tighten and seal an otherwise soft and porous clay, and serve as a whiter base to brighten glaze colors.
Engobe recipes should be similar to the body to which they will be applied, with little frit or boron added. They should also be low in flux to preserve opacity. Excessive flux will increase firing temperatures and introduce stresses between the engobe and the underlying body that can test their fired marriage with cracking or shivering.
This is a common problem that can be caused by applying an engobe to dry ware and then glazing it. It is essential that the engobe be applied at leather hard stage – its body-like makeup enables a plastic bond to develop during drying and its fire fit (body-matching fired shrinkage and COE) will keep it in place through firing.
A glaze is a mixture of powdered materials that are fused to a glassy coating when dried and fired. Glazes are typically applied by spraying or dipping. They are formulated to bind with the clay surface in a zone of adherence called the clay-glaze interface. During drying the slurry particles draw together and shrink, with more vitreous bodies shrinking more than others.
Digital Inkjet Printing Tiles
Inkjet printing is a common technology used in home and office printers to produce photo-quality images. The same technique is now being applied to ceramic tile manufacturing to create unique designs and patterns that add sophistication and visual appeal to interior spaces.
The specialized ceramic digital ink used in this process is able to hold up against the high temperatures involved in the firing of ceramics, so the printed patterns remain vibrant and intact after they’re glazed and fired. Using this innovative process, manufacturers can create tiles that mimic the appearance of natural materials, including wood-look tiles, stone-inspired colors, and abstract designs.
Ceramic digital printing is also an excellent option for producers looking to increase efficiency and decrease production costs. The use of a digital printing machine eliminates the need for complex and costly equipment like rollers and silk screens, making it a more cost-effective alternative to traditional methods. In addition, the digital inkjet printing process can produce smaller runs than rotocolor or custom screen printing, which reduces the amount of inventory and storage needed.
LOPO utilizes a leading Italian digital tile printing machine to create sophisticated new designs on terracotta. Combined with high-quality ceramic digital ink and advanced printers, the LOPO 3D Inkjet Printing Tile series provides exceptional reproduction of natural textures such as marble and wood, as well as highly creative new patterns.
Crystalline Glaze Tiles
Crystalline glazes are a form of surface decoration on ceramic pieces. It combines the use of frits and pigments with a very low firing temperature and slow cooling rate to create a unique crystalline structure on the glaze surface. These crystalline structures are very popular in modern designs because of their unique look and durability. The technique is usually used on high-end floor tiles, although it can be applied to other types of pottery as well.
Four different glaze formulations for porcelain stoneware tiles were investigated for their tribological properties by means of analytical tests (thermal analysis, Vickers hardness) and technological ones (surface abrasion test). The studied glazes were obtained from commercial gach viglacera 30×60 products manufactured by Colorobbia Italia S.p.A, Fiorano Modenese, Modena, Italy and were prepared following the specific recipes reported in Table 1.
To carry out the surface abrasion test, 30 x 30 cm unfired tile bodies were coated with engobe and glaze slurries having a density of 1470 kg/m3 by airless application. Then, decorative patterns were printed on the engobe layer using a digital printer. The slurries were single-fired at a heating rate of 30 degC/min and a peak temperature of 1205 degC. The resulting disks were dry-cleaned and grinded to a particle size smaller than 0.063 mm and then analyzed by X-ray diffraction (XRD) on an Empyrean Series III, Malvern Panalytical Ltd., Malvern, UK.
Lappato Finish Tiles
The lappato finishing technique represents a sophisticated middle path between matte and polished tile finishes, striking a balance that creates visual depth while preserving surface texture. The technique uses selective abrasion to partially polish tiles, leaving sections with a glossy sheen while other areas remain matte, creating a distinct appearance that reflects light without eliminating texture. The result is a unique blend of texture and shine that adds elegance to interiors, but requires special care to maintain.
The quality of diamond lappato abrasives is crucial to the success of this finishing technique. The hardness of premium diamond abrasives (typically a 10 on the Mohs scale) exceeds that of ceramic tile surfaces, allowing for efficient and controlled material removal without excessive wear on the abrasive tools themselves. In addition, the use of water lubrication helps control temperature and prevent overheating.
When selecting abrasives for this process, it’s important to consider the particle size of each individual diamond component. Larger diamond particles provide a more textured look, while finer diamonds produce a smoother finish. Achieving a consistent lappato finish is also significantly influenced by the type of bonding used to hold the diamonds to the abrasive tool. Resin-bonded diamonds offer superior performance, while metal-bonded diamonds offer increased longevity.
After abrasive treatment, lappato finish tiles should be thoroughly cleaned with a pH-neutral cleaner to remove polishing residue and prepare the surfaces for grouting. In addition, a simple water break test can be performed to evaluate consistency and ensure that the abrasive process has produced a uniformly consistent texture. Splash a small amount of clean water onto the surface; it should sheet evenly without breaking, indicating that the tile has been treated uniformly.
