One of the draw-backs to pastels is their infinite smudgability. Mostly the artwork survives the scanning pretty well, but there are occasional smudges. Luckily these are easily remedied in Photoshop.
When I get my DVD of artwork scans, The first job is open each illustration in Photoshop, one at a time, and carefully look them over, checking for smudging or flaws.
Another job down! You can see short films with more information about how I illustrate my picture books here.