Heritage tile refers to hand made tile by artisans in California and the West coast. These tile makers who brought tile making traditions from England and Spain. They are unique hand made craftsmen.
Ceramic bodies and glazes are mostly custom hand made. Each tile maker has its formulas and tradition.
There are two ways of making these tiles.
Wet clay: these clay bars come in wet form. Clay needs to dry for several days; then it is shaped into the desired tile. Finally, it is fired the first time and then fire a second time. Imagine how labor-intensive this process is.
https://www.countryfloors.com/crossings/ This collection made by Karen Paterson is the ultimate hand made tile. Resembling encaustic cement tiles, each vein is a unique color poured into the mold.
Dry clay: this is easier and quicker. However, one is limited in sizes and shapes dry clay can take shape. The end result is more of a price tile but limited in shapes and dimensions.
Most heritage tile makers use old Scott electric kilns. These kilns have small capacity but produce unique and beautiful tile. Moreover, each kiln will hold no more than 30 square feet. They are dedicated artisans.