Horta, a grey hand-moulded brick

The facade bricks (non-perforated) have five sand covered sides and one side with possible oblong groove. The structure looks rugged with fine and irregular grooves in the sandy surface. The baking process takes place in a gas-heated tunnel oven under slightly reduced atmosphere. The homogeneous mixture of accurately predetermined proportions of manganese oxide within the loam is responsible for the light grey colour of the brick. The colour variations show a pastel shade ranging from grey to beige, interspersed with yellow, reddish-brown and black nuances. The colours shown are a near reflection of reality.