Brick has been a popular building material for thousands of years, as ample historic structures can attest. Several different methods can be used to make brick. As a general rule, the brick making process involves mining clay, mixing the clay with sand, creating bricks, and then firing the bricks so that they harden. Once fired, the bricks are extremely strong, and they can be various colors and sizes, depending on where they are made. Many people associate bricks with the color red, but they can also be yellow, nearly white, or cream, depending on the ingredients used.
Historically, brick making was accomplished by hand, with the clay and sand mixture being packed into molds, allowed to dry, and then fired. Molding is still a technique used in brick making today, except that it is accomplished with the use of large steel molds into which the raw materials are packed hydraulically to achieve a very dense, evenly textured brick. These molds are often set up on a rolling conveyor belt which moves the bricks through a kiln for firing as they are made.
Another option is extrusion. With extrusion, pressurized materials are run through a machine which molds the materials into long strips which are cut into bricks. The bricks are in turn allowed to dry and then fired. With both methods, it is possible to stamp the brick with various designs, if desired. Some companies stamp their bricks with information about where they are made, while others may add decorative designs to their bricks.
Adobe brick, a building product still used in some regions of the world, is sometimes still made by hand in the traditional way. Small rural communities in regions like Africa may make their own bricks for building with available local materials. Adobe and the closely related mudbrick are made without firing, and the entire process can take weeks, as the bricks may take some time to cure. While curing, the bricks can be stamped with designs, and decorative elements can also be inserted into the brick.
Bricks are also still molded by hand for commercial sale in regions of the world where labor is cheap and readily available. Advocates for people living in slavery and children who are laboring below the legal working age have exposed a number of brick making operations in nations like Pakistan which utilize illegal labor techniques to produce extremely cheap bricks for sale. In these regions, the use of illegal labor for brick making is more cost effective than purchasing the machinery to mass produce bricks.