Monday, February 07, 2011

Pencil cleanup in Photoshop

I've been trying to work out the best way to use just my pencil art to make comics, without inking it. Not for my main feature, but for fun side-projects, just to cut out some of the donkey work, to knock out quick comics for shows and things like that. I have a pretty serviceable pencil line - I've spent years practising not hashing around shapes but drawing things straight out.

The problem has been turning that greyscale art into something I can colour quickly with flood fills, which is to say, a grubby grey page into nice clean B&W line art. Here's how I did the image above.

1. Scan page at 600dpi greyscale.

2. Set the magic wand tolerance to 30, non-contiguously select the "paper" and fill it with white

3. Deselect the paper

4. Filters > Blur > Smart blur ; Radius: 4, Quality: High, Threshold: 75.4, Mode: Normal

5. Select the white area with the magic wand, non-contiguous, invert selection and fill with black

6. That should do it!

This didn't work perfectly on every image I tried it on - and fine details will suffer somewhat, but have a play with the settings - the basics are all there!

If you find this saves you a lot of time, maybe whole years of your life, why not visit my shop and express your gratitude in the only language my venal mind understands.


Virtualbri said...

Even if it's not perfect, your example looks shockingly good for something automated. I hope it helps cut the drudgery down.

Tony said...

I'll try this out for myself! But I have another suggestion for you: don't pencil with graphite. You can use a colored pencil (I have a dark blue mechanical pencil I use), and then scan greyscale.

Graphite, when it builds up, is shiny. The scanner has a bright light, and sometimes the graphite reflects the light and comes out white instead of black.

John A said...

If only, Tony! I never liked the feel of blue mechanical pencil leads and I used to snap them endlessly (a friend complained that he could hear them breaking as he clicked his pencil the other day!)

But I will certainly have a go, just for my own curiosity. No beating the lovely liquid feel of graphite though!

Paul said...

You may be able to do the same with fewer steps using the levels adjustment tool.

John A said...


I spent ages playing with the levels - weeks! I would always get holes in my lines. Smart blur is the best way to homogenise the pencil lines.

Kat R said...

Seems a pretty effective way of working and must certainly speed up the process (always a plus)

The way I always clean up linework (inked or straight pencil) is to first adjust the layers then use the dodge tool to get rid of straggler marks before copying everything to a new layer in channels and then loading the selection to a nice transparent layer. Sometimes I like to fill the selection with a sepia or sanguine tone instead of black too.

I'll have to try using blur though since you say it keeps away those annoying white spots!

Niki Smith said...

I've found I like a different set of filters for cleaning up my lineart, but it seems similar in the results--

try out:
Filters > Stylize > Diffuse > set to Anisotropic

(then I just use Threshold to get it to a perfect black/white)

Anonymous said...

If you really want quick and easy you should work straight up in a vector tool like Illustrator! Oh, wait...

donnafan said...

I've found that live trace in illustrator works wonders and is nearly zero effort.

Gonzalo Pacheco said...
This comment has been removed by the author.
Gonzalo Pacheco said...

Thank you, this has helped me a lot, even with my non-steady pencil line (I have a lot left to practice and learn, but I'm on the way).
I adjust actually the Brightness/Contrast at the beginning to compensate the reflection of the light by the graphite.

Unknown said...

Have you tried scanning your drawings, taking them into Flash and then using the fill/trace option to create your lines? It makes them into vectors and even though there's a bit of tidying up afterwards, once you get the hang of it, it's quite quick.