Directory
Sketch cleanup
Make a scan easier to color without asking a model to redraw the line you already made.
Clean a pencil scan without redrawing it
Set black and white points on a copy so the line is easier to color and the drawing stays yours.
Lift stains without redrawing the picture
Use inpainting only on specks and paper damage, on a duplicate, and compare it to the scan.
Trace to vectors, then redraw the line
Use an auto-trace as scaffolding for a logo or a clean ink drawing, not as the finished contour.
Turn a pencil scan into a transparent line
Drop the paper out so color can sit under the drawing you already made.