See these paintings at Glitch, 48-49 Old Market St, Bristol BS2 0EX
Bitumen paint is made to repair a leaking roof. It is dreadful stuff to work with, sticky, stinking and as black as can be. It is like the dregs of a barrel of crude oil, but when dried on a painting it can be a sublime, rich, and deep black. Pure black like Japanese lacquer, but with a velvety softness. This contrasts with a thin transparent wash of blue through which light shines and bounces back off the white base so illuminating the colour from behind. Thin strips of cast silver coloured metal (mostly tin) are embedded in the paint. Squeegees scraped through the bitumen brings colours from bedhind creating interference patterns.