This paper is at least 24 years old and very yellow (even though my dirt cheap scanner rather conveniently bleaches out the age stain). If I use the eraser too much I leave a whiter-than-white mark on the sheet, so I'm being very careful about the sketching, and I'm having to do the shading absolutely right first time.

If I'd thought about this properly before I began, I would have gone and bought myself a brand new sketch pad