Non repro blue pencils

[nowhereman]

Where can I buy them?

[Baloodoo Bill]

Any art store and most larger stationary/office supply stores.

May I suggest Eberhard Faber's "Col-erase" brand #1283 (light blue). Slightly darker than non photo blue, it's more visible to the naked eye. Also less waxy and thus, erasable, because we all make boo boos.

When scanning, use your red filter and the blue will show as black, use the blue filter and the blue disappears.