Fabric : Muslin

Muslin is most typically a closely-woven unbleached or white cloth, produced from corded cotton yarn. Wide muslin is called "sheeting". It is often used to make dresses or curtains but may also be used to complement foam for bench padding. Muslin breathes well, and is a good choice of material for clothing meant for hot, dry climates.

It ranges from rustic muslin, with rough texture, to ...
... soft muslin, good enough for nappies.
When sewing clothing, a test or fitting garment may be made of inexpensive muslin fabric before cutting the intended expensive fabric, thereby avoiding a costly mistake. The muslin garment is often called a muslin and the process is called making a muslin.

[From Wikipedia, the free encyclopedia]