"If we delve back through the historical #record, back past the Plastic Age, we come to the Age of Linoleum." With a brush, Prof. Chifley dusted off a thin, rectangular square and held it up for the field class to see. They were at an excavation site of a mid-20th century town.
"It was totally natural," Prof. Chifley said admiringly. "A #blend of linseed oils and fillers like sawdust on a burlap backing."
The students examined the ancient floor covering in wonderment.