Got a line drawing in reasonably thick black pen but not super dark, on graph paper. We’ve scanned it – how to remove the graph paper lines? They are the traditional pale blue.

james@fromthesticks.co.uk – send it over if you want, i’ve a quiet Friday on the cards.

If they are a lot lighter than the actual drawing, could you use a threshold adjustment layer?

I would add a Hue/Saturation adjustment layer on top.
Then dropdown the select box with ‘Master’ written in it to ‘Cyans’.
Then boost the lightness until they disappear. If they don’t fully disappear, then also drop the list down to ‘Blues’ and do the same.

Please, post it up so that we may help you.

Do post it up Molls. I’ll sort it out for you

No. I’ll fix it right up for sure.

Hue/Saturation/brightness adjustment layer then use the dropper tool to select the blue (which may be blue or either cyan) then lighten and remove the saturation.
i would be tempted to take it to a blown 255/255/255, flatten and then use a clone stamp in darken mode so that the black pen remains untouched but the paper white/texture can be copied over the pure white areas left by removing the blue lines.
if you want the white background to absolutely pure white then levels will sort that with the mid point adjusted if there is any grey shading you want to retain.

1. Mode > Grayscale

2. Image > Adjustments > Levels

Adjust level sliders, pull left slider right until faint lines disappear, pull left slider right to bring up contrast in dark areas.

cpon – Member

1. Mode > Grayscale

2. Image > Adjustments > Levels

Adjust level sliders, pull left slider right until faint lines disappear, pull left slider right to bring up contrast in dark areas. I wouldn’t do this personally. At the moment you’ve got a useful differentiator between light intentional marks and the blue lines. If you convert to greyscale you’ve thrown this out.

Another useful method is to use a Black & White adjustment layer and boost the colours you want to lose. Very similar results to the method I posted above.

Thanks folks.. sort of there now.. only issue is that the black lines aren’t really solid, you can see white flecks in them now.

We want it to look like a kids colouring book drawing.

And I’d love to post it up but it’s not our drawing and would not be fair on the artist to have it mocked on the internet.

Ping it to me at cokie.stw(at)gmail.com, I’ve got something that should do it.

molgrips
would not be fair on the artist to have it mocked on the internet.

Oh and thanks for the offers to do it but there might be many, and we’d like to gain the skills for the future.

Okay, in that case try Adobe Capture– download on your phone/tablet and have a play.

If the lines are blue and the text is black use image>adjustments>selectivecolor and take CYMK sliders out of the blues and the cyan. Then any color left there after. They’ll disappear eventually. you lose some out of your black as well doing this but shouldn’t be too much.

Oh and thanks for the offers to do it but there might be many, and we’d like to gain the skills for the future.

If this is going to be a regular occurence can I suggest you just buy some plain paper? 😀

i would just copy the red or green channels into a layer and use curves to tidy it up.

There will be multiple ways of doing it. Possibly hundreds.

If this is going to be a regular occurence can I suggest you just buy some plain paper?

Artist uses graph paper for a reason, they are symmetrical and geometric.

I’d pick the background colour with the dropper, zoom in and pour the paint bucket onto the lines. It won’t get the edges of the lines as they’ll be paler, but if you fiddle with the tolerances on the paint colour you’ll get most of it, then you can use the techniques above to remove the last bit; despeckle is also good for removing small bits of colour. Just remember to work on a copy as it may take a few attempts.

Maybe in future your artist could use plain paper with a really boldly printed grid on another piece of paper beneath it ?

Used to do all my artwork on sheets printed with a pale cyan graph grid, which would be shot on lith film, which couldn’t ‘see’ cyan, but with digital scanning and photography, such a process is no longer an option, but there are certainly ways of selecting blues and cyans in Ps selective colour that should remove most of the grid lines, and other processes as others have suggested.
Once you’ve got a process that works successfully, record it as an action on a ‘F’-key, and just run the action for each new job, it’ll save a lot of work in future.