It would really depend on the drawing – hard to tell without seeing it. Is the pencil drawing grey/monochrome? How dark/discoloured/messy is the background?
Here’s the result side by side with the original for comparison.
Anyhoo, if I was to take an extreme case of discoloured dirty background as an example such as this, here’s how I would attempt to clean it up.
Not the answer you’re looking for? Browse other questions tagged adobe-photoshop print-design cmyk drawing or ask your own question.
Scan it in colour. Apply a Black and White adjustment layer. In this example I moved the sliders for yellow and red to try to get rid of the background. Apply a Levels adjustment layer, and bring the shadows up by moving shadows slider until it touches the left edge of where the histogram shows there is some detail.
Add a new layer, set the paint brush to white, and paint out any spots or dust remaining on the white areas.
I’m trying to work the best way to remove dust, bring the background up to white without losing detail, whether I should convert the images to a greyscale format and if there are any other gotchas.
There are lots of ways I could approach this, I’m just trying to find a way that will be as sensitive as possible to the very fine detail in the drawings and cause as few problems as possible for publishing. Is there an accepted method for doing this?
I have a selection of pencil sketches that need to be prepared for print in a book (think standard paperback).
Envato Market has a range of items for sale to help get you started.