A typical slate landscape is rather hilly, with undulating plateaux and gentle protuberances riven by rough-looking valleys with cliff-like sides. The slate hills in Germany – in the Rhine Valley and Thuringia – are like this. The so-called ‘blue gold’ mined there has over the centuries produced a rich roofing (Altdeutsche Deckung) and house-fronting culture. Slate is still mined in Fredeburg (in Sauerland, central Germany), in the Moselle valley, in the nearby Hunsrück and in Thuringia – for house-building, and also for articles like our blackboard.

The board is attached to the wall by hanger bolts; the gap between board and wall can be adjusted by means of a hexagonal nut – to give an even appearance. The cap nuts come in two formats, nickel-plated steel and brass.

Where the foliated (schistose) rock from the Devonian comes to the earth's surface, it forms peculiar mountain landscapes with undulating plateaus and mild heights, which are furrowed by rugged valleys with cliff-like rising valley walls. In Germany, this is the case in the Rhenish and Thuringian Slate Mountains. There, the "blue gold" has become culture, namely building culture, as facade cladding or roofing in the typical local geometry or the famous "old German covering". In Germany, clay slate is still mined in the Sauerland (Fredeburg), on the Mosel (Katzenberg), in the Hunsrück and in Thuringia - for construction purposes, but also such, which is the subject here: in addition to roofing slate, there are also known as the table and stylus slate.