The kneaded eraser, also known as putty rubber, is a tool for artists. It is usually made of a grey or white pliable material (though it can be found in many different colors, ranging from green to blue to hot pink) and resembles putty or gum. It functions by adsorbing and "picking up" graphite and charcoal particles, in addition to carbon and pastels. It does not wear away and leave behind eraser residue, thus it lasts much longer than other erasers.
Kneaded erasers can be shaped by hand for precision erasing, creating highlights, or performing detailing work. They are commonly used to remove light charcoal or graphite marks and in subtractive drawing techniques. However, they are ill-suited for completely erasing large areas, and may smear or stick if too warm.
Although kneaded erasers do not wear away like other erasers, they can become saturated and unable to absorb any more graphite or charcoal. In that case a kneaded eraser will actually leave marks on the paper instead of erasing them.
Different colored erasers can be blended together, creating a larger eraser that is a new, unique color. New kneaded erasers can be stretched and compressed easily, changing their texture and form.
Kneaded erasers are also useful for making impromptu sculptures to sketch from. Kneaded erasers are mostly used for slightly erasing but not fully erasing the content of graphite. It has great plasticity and can be molded and shaped into desired forms for ease of usage.