mull

Preferred label: 

Coarse, loosely woven cotton fabric used principally to line the spines of edition bindings.

Etherington & Roberts (1982)

Roberts, Matt, Don Etherington, and Margaret R. Brown. 1982. Bookbinding and the conservation of books: a dictionary of descriptive terminology. Washington: Library of Congress.

Additional reference: 
http://www.cool.conservation-us.org/don/dt/dt2292.html (modified)
Hierarchy: 
Broader concept: 
Broader partitive concept: 
Top concept: 
materials