this phrase relates to the scars that coal miners often had as a result of working underground in very difficult conditions. The scars were blue in appearance and were the result of small particles of coal being trapped under the skin. most older miners had them and this was a visible reminder of their occupation and where they came from. these coal dust stained blue scars on the faces of miners are sometimes also caused by mine explosions - a terrible reminder of the hard working conditions in the mines.as a design for life is a reaction against the suspicious death of working class values (see a design for life [phrase]), the idea of wearing miner scars as a sign of dignity, in general as a symbol of being part of the working class, fits into this context. [many thanks to Harry Cunningham for providing this information].