Red brick with a touch of blue
The brick has a red base, and the hues vary from burgundy colour to purple with blue violet shades. The shading is obtained from a mixture of lössial clay with reddish brown, granular and moist sand and various melted oxides in accurately defined proportions.
The facing brick (non-perforated) is sanded on five sides, and provided with a possible oblong sloping groove on one flat side. The structure is formed by a rough appearance with fine and irregular grooves in the sandy surface. The baking process is done in a gas-fired tunnel kiln under a slightly reducing atmosphere.