www.floortrendsmag.com/articles/83667-symbol-sets-armstrong-linoleum-apart-from-vinyl
Symbol sets Armstrong linoleum apart from vinyl
June 12, 2002

Armstrong Marmorette linoleum
Genuine linoleum from Armstrong, such as the company's Marmorette sheet linoleum line, now carries a special "square-in-a-square" symbol on all retail samples to distinguish it from more familiar vinyl floor products.
Only recently making a resurgence among flooring consumers, genuine linoleum contains cork and renewable raw materials such as linseed oil, limestone, resins, wood flour, mineral pigments and jute.