They are archival. Writing doesn't fade and doesn't react with the paper you write on. Very important if you are writing something that may need to be read 100

They are archival. Writing doesn't fade and doesn't react with the paper you write on. Very important if you are writing something that may need to be read 100 years from now. Writing is erasable. By gently using an art gum eraser it's possible to remove and fix mistakes because there is no ink that soaks into the paper. Pencils are pressure sensitive. You can have great control over the shape and darkness of the lines you draw. They work extremely well with waterproof paper, much better than a pen, even the "special" pens that companies such as Rite in the Rain will sell you. Pencils never dry out and you always know how much "ink" you have left by just looking at them. I've personally use pencils as a museum curator, as an artist, as a field biologist and of course as a student.