rough straw cardboard
A coarse, thick cardboard traditionally made from straw; used for stiffening or backing in crafts and bookbinding.
low-grade lining paper
Archaic term for a cheap, low-quality paper used as a lining or padding material.
Rough straw cardboard was often used for the covers of old books.
There are descriptions in Edo-period documents of using low-grade lining paper for backing.
The term literally means 'horse dung paper,' likely referring to the coarse, straw-like appearance or the use of straw in its manufacture. The exact origin is uncertain.