Kustukumm

Kustukumm is the Estonian word for an eraser, a small implement used to remove pencil marks from paper. Erasers are widely used in education, design, and office work.

Most kustukumms are made from natural rubber or synthetic polymers and come in shapes such as rectangular blocks, cylinders, or plastic- or wood-encased forms. Some variants are kneaded, soft putty-like substances that can be molded for precise erasing and for lifting graphite without heavy rubbing.

Erasers work by friction that lifts graphite particles from the paper surface. Softer erasers erase more cleanly but can smear or wear quickly; firmer erasers remove more material with greater abrasion. In some cases, ink marks are not fully erasable and require specialized tools.

Types include rubber erasers, vinyl erasers, kneaded erasers, and self-cleaning or dust-free varieties. Some are designed to minimize paper abrasion or to erase graphite only; others are used for drafting and art.

The concept of erasing pencil marks dates to the late 18th century, with commercial erasers becoming widespread in the 19th century. In Estonia, kustukumm is a standard item in schools and offices and is produced by many stationery manufacturers.