Is there any eraser that can erase charcoal?
I've been trying 3 different brands of kneaded erasers (Faber-Castell, Prismacolor, and an unknown brand) and nothing has happened.
Kneaded erasers are usually perfect for erasing charcoal.
However, when it comes to erasing charcoal, the success of kneaded erasers depends on a few factors:
The type of paper
I've experienced problems erasing charcoal from papers with very low to no grain (this includes the typical A4 printer paper, on which it is hard to draw with anything to begin with).
Select proper paper when drawing with charcoal: a medium to heavy weight paper with a fine to coarse grain (the charcoal needs to be able to deposit particles within the structure, but the kneaded eraser equally needs to be able to pick it up from there). Anything smooth and flimsy is usually a subpar choice for charcoal.
The quality of the charcoal
Cheaper charcoal tends to have an inconsistent structure. If you use charcoal that deposits particles of varying size or at times doesn't leave a trace at all, stop using it and buy other charcoal (if from a reputable brand you might want to ask your money back).
These deficiencies are due to the quality of the burning process, and the type of wood and the part of the tree or plant used.
The pressure applied when drawing with charcoal
When drawing with a piece of good quality charcoal on good quality paper, the lines produced should have a consistent hue. Get a feel for letting the charcoal stick glide over the paper, without consciously applying pressure. Depending on the technique and work method, only after the initial linework is done should pressure be applied to create different hues. Generally, the harder you push the charcoal, the harder it will be to remove.
The condition of the eraser
Lastly, of course, there is the eraser itself. For the best results, use a clean or well-kneaded eraser. Kneaded erasers become saturated when used, and at some point it might be hard for them to pick up anything at all.
I myself have not encountered bad kneaded erasers yet, but the quality could also differ between brands. There is a difference in how kneadable the one is in comparison to the other, but this is a matter of personal preference.