Watercolor vs. whiteout

The old graphics trick for this is to do the illustration on clay-coated illustration board, and lightly scrape away (small areas of) unwanted ink with a very sharp x-acto or razor blade. As long as you don't scrape through the white clay coating it should take the paint without resisting. Now I know this works for marker and gouache, but not being a watercolourist I don't know how receptive it would be to watercolour. Forget the whiteout.

Here is a poser. I illustrate in color with black india ink and transparent watercolors on bristol board, usually plate finish. If I make a mistake with my ink line, how do I correct it so I can still apply a color wash? Whiteout seems to resist everything, from wash to colored pencil, etc., so any correction I make is glaringly obvious. I need to be able to correct unwanted ink lines and still apply color over the corrected areas. I would appreciate any helpful suggestions and/or resources on this matter. Thanks in advance!

Try full strength bleach

Correct answer, you can't! Pen and ink is notorious for being un-correctable. Most correction efforts will fall short of the mark. You could try another tack... use a water soluble pencil to lightly draw in your lines first. Use a color that will be part of the final color palette. When you are satisfied with the entire drawing ink your lines. Adding a watercolor wash will dissolve the colored pencil into the wash.