all about erasers - part 3
Kneaded erasers are soft, easy on paper, and can be formed into delicate shapes for greater precision in erasing. They are essential for subtractive drawing techniques like lifting out highlights and reflections.
Kneaded erasers collect graphite and charcoal dust and can become a bit messy. This is why they aren’t ideal for clearing large areas on a page. They’ll leave smudges.
It is impossible to really clean a kneaded eraser. You must literally knead the eraser, pulling it and folding it in on its self, in order to incorporate the graphite or charcoal dust into the eraser. Ultimately, your kneaded eraser will become saturated with this dust. It will be big and black and will leave more marks than it picks up. This is a sign that it’s time to replace your kneaded eraser.