Oil bread
In the history of printing, the term oil bread refers to the bread that was dipped into the heated linseed oil as an indicator for the production of linseed oil varnish. If the bread was crispy brown, the process of obtaining linseed oil varnish from linseed oil by heating was complete. Linseed oil varnish was in turn an essential component of the viscous and quick-drying printing ink that Johannes Gutenberg had developed , which also contained soot.
The printer's journeymen liked to eat the bread.
swell
- Eberhard Dilba: Typography Lexicon . 2nd edition, Grevenbroich-Wevelinghoven 2008.