Digital Comic Colouring – How I Do It, Part One: The Preamble

A few people have asked me of late, “Who are you?! How did you get in here?! It’s 3am! Get out of my house! I’m calling the police! etc etc”, but a few more people have asked how I ‘do’ my comic colouring.

Short answer – I use Photoshop.

Now, I fully realise that that’s probably not the level of detail you were after, so I’ll elaborate a bit. Well, no, a lot. Sorry in advance. This will take a few blog posts…

To start with, I’m using Photoshop CS6. These techniques can all be used as far back as Photoshop 7 & 5 to varying degrees, but you might find the menu’s and options have changed a bit so you’ll need to do some detective work specific to YOUR software. I ain’t taking responsibility sunshine, no sirree.

No two colouring jobs are the same, but there will always be a fairly consistent set of practices you can use to digitally colour your work. So, lets look at the standard stuff, and break this whole process down into manageable bits.


This is a fairly crucial bit. You need art to colour in the first place. It can be your own, it can be sent to you by an editor. The artwork itself will need to be prepped before you colour it. When you first receive / scan the art (or digitally draw it), make sure you work at least at 300DPI. DPI is ‘dots per inch’, and equates to the screen resolution of the image. If you are drawing for use solely on websites, then 72DPI is fine. if you plan on printing your work, 300DPI should be your minimum. 400 or 600 is even better, but in my experience, if you’re printing out at A4, US Comic Size, Letter or smaller, then 300DPI will work fine. 200DPI works ok, you can get away with that, but really 300DPI is your ideal. You can do the DPI check from Photoshop’s Image menu (Image>Image Size option).

Make sure the art has enough space around it to account for the printing process. You might need to add 3mm of dead space around all the edges – this is called Bleed, and allows you to put colours or imagery that will run off the page without leaving an ugly thin white line on the page edge. Also make sure that the gutters (that’s the space around your panels) have at least 15mm or so of space before it hits each edge of the page, to make sure imagery doesn’t cut off when they trim the book after it’s printed. Ask your printer for their ideal specifications on this.

Screen Shot 2014-08-30 at 01.26.28

An example of ‘dirty’ art – visible construction lines and artist notes in the guttering. Paint out the notes, and use the Black & White function to remove the blue/red lines. Art by Dan Harris, from Lou Scannon #7.

Using the Black & White sliders to remove blue and red lines

Using the Black & White sliders to remove blue and red lines

The next step in prepping the art is to actually clean the art up. Now, it might be fine. It might be pristine, black and white art, level, no blemishes, ready to go. Great. If that happens, fab. But frequently you’ll get art that isn’t quite ready to be coloured up yet. There may be fingerprints on it, dirt from the scanner, visible pencil lines (blue, red, grey), outright mistakes in the art, it may be tilted by a few degrees, you get my drift.

If the image has been sent to you as a Bitmap mode image, then convert it to Greyscale mode to start (Image>Mode). Use a ratio of 1 to keep the document the same size. If it’s been sent as a TIFF or high res JPG, then I tend to use the Black & White option from the Image>Adjustments menu. This option is great, and using the sliders it very handily lets you strip out any visible blue pencil construction sketches, or red pencil, or both. If your Photoshop doesn’t have this option, then removing red or blue pencil can be achieved by deleting the Red and Blue channels in the channel menu before you greyscale it. Then go to Image>Mode to Grayscale the art. Now, you’ll also probably want to use the Levels tool under Image>Adjustments to really crush the blacks and blow out the white. Use the Brush tool (100% opacity, white colour) to draw out any unwanted lines, dirt, fingerprints etc.

“WOAH!!!” I hear you say, ” Why the heck are you turning your document to grayscale?! Aren’t we COLOURING this thing?” Well, yes, we are. But grayscaling the document helps us clean up the image, and it’ll help us better isolate the white background from the black lineart later on. Trust me. I ain’t gonna steer you wrong. Well, not intentionally.

Finally, in the Layer pallet, double click your lineart layer (which should still be marked Background at this point) and click OK in the resulting pop-up box. This will convert your art from a background layer into a proper layer.

Section Recap!

Scan / Draw / Receive art.
Make sure art is 300DPI for print, and has appropriate bleed and guttering.
Clean up any dirt etc using Brush tools.
Greyscale the art, and Level the image.
Convert the Background layer into a proper layer.



There are two ways of removing the white backdrop from your artwork, so you can add colour layers underneath it. There’s the quick way, and the RIGHT way. I’ll tell you the quick way, and then tell you why the right is actually the right way, even though it’s more involved.

Setting the layer mode from Normal to Multiply.

Setting the layer mode from Normal to Multiply.

The Quick Way – In the Layer pallet, there is a dropdown menu which is your Layer Blending Mode. It’s default setting is Normal. Make sure you’ve got your lineart layer selected, then change that dropdown to Multiply. It’ll look the same but now anywhere that’s white on your lineart layer will allow layers below to shine through. (Complicated reason why – Photoshop takes the colors from the layer that’s set to Multiply, and multiplies them by the colors on the layer(s) below it, then divides them by 255. You don’t need to worry about the maths though – just know that with this mode black becomes opaque, and white is completely see-through.) That’s really it. Very quick, very effective… but also very limited. This method doesn’t allow you to colour directly on the lineart layer without messing up the effect, and it’s for that reason I tend not to use this method.

The RIGHT Way – This way actually removes the white areas of your art completely, leaving only those lovely pristine black lines. But it’s a little more involved. Sorry. First, select the ENTIRE page (Select>Select All). Copy it (Edit>Copy).

Go to your Channels pallet (it’s under Windows>Channels if you can’t find it), then click the little upturned corner page icon at the bottom of the pallet to make a new channel (which will be named Alpha 1).

The Channels Pallet.

The Channels Pallet.

Hit Edit>Paste to paste your lineart into this channel. Now got back to your Layers pallet where your art is still selected. Take a deep breath, and hit the Delete key, wiping your art off the screen FOREVER. “But wait!!!” I hear you cry, “I need that art!!” Don’t fret – it’s still there, just in the Channels. We’re going to use the art from the Channels to make a new version of the lineart, a version without the white colour! Aaaah. Delicious. Go to Select>Load Selection, check the Invert box, then select Alpha 1 from the dropdown list.

Make sure you've checked the 'Invert' box on this bit too.

Make sure you’ve checked the ‘Invert’ box on this bit too, it’s hidden under the dropdown in this graphic..

Your layer will now have the ‘marching arts’ of your lineart.

The lineart now appears as a selection,

The lineart now appears as a selection

Next, simply go to Edit>Fill, and fill the selection with Black (using this option uses a black colour that is already the equivalent of Overprint Black, for a nice, rich dark colour). This will give you a layer that’s just got the lineart lines, and no white!

Black lines, no white backdrop!

Black lines, no white backdrop!

Finally, check the Lock Transparent Pixels icon in the Layer Pallet, and this will allow you to colour only the lineart and not the transparent bits.

Lock Transparent Pixels - very useful later on!

Lock Transparent Pixels – very useful later on!

If you’re working for Web or devices only, Image>Mode and set it to RGB (but don’t flatten the image).

At this stage the lineart is fine for web or device use, but we need to do a tiny bit more prep before it’s good to be used for print.

As we’re working for print, Image>Mode and set it to CMYK (but don’t flatten the image). Make a new layer, place it under the existing lineart layer. Just like we did before, Select>Load Selection, check Invert, then select Alpha 1 from the dropdown list. Your layer will now have the ‘marching arts’ of your lineart again, but now we’re going to want to contract it by 1 pixel from all of it’s edges – go to Select>Modify>Contract, and input the value as 1, then hit OK.

Contracting the selection for the trapping layer...

Contracting the selection for the trapping layer…

Next, go to Edit>Fill, but instead of using Black, use Colour, and set the Colour Values as 0%K, 60%C, 30%M, and 30%Y. This will fill your selection with a slightly greyish green colour, which will be hidden underneath your lineart. You can go ahead and then lock this layer.

Input the CMYK values in the bottom right hand corner of the colour picker.

Input the CMYK values in the bottom right hand corner of the colour picker.

What we’ve just created is a ‘trapping layer’. Trapping is a term most commonly used in the prepress industry to describe compensating for misregistration between colours on a multicolour press. This misregistration causes unsightly gaps or white-space on the final printed work. (i.e. a thin white line between a block of colour and the actual lineart) Trapping involves creating overlaps (spreads) or underlaps (chokes) of objects during the print production process to eliminate misregistration on the press. This trapping layer ensures that a white misregistration line is minimised or eliminated. Nowadays, this is rarely an issue, and this generally applies to large print runs that use a CMYK press – smaller print runs that rely on digital printing largely avoid these problems, but I like to use a trapping layer anyways. Force of habit. Below is an example of a badly misregistered comic,  from….

Note how misregistered colours leave telltale white lines

Note how misregistered colours leave telltale lines

Finally, a bit of housekeeping – name your layers, make one last new layer and fill it with white, and place it at the bottom so you can see what you’re doing later… and then save your new PSD file. Yeah, I know, it’s complicated. But trust me, it works. You don’t have to UNDERSTAND all of it, but you’ll get a more flexible result this way… Oh yeah, save and save OFTEN.

Oh, as this method is long-winded, my tip – record an Action of this, and store it in the Actions pallet. A real time saver later one.

Section Recap!

Quick Way – Set Lineart Layer to Multiply mode.
Make a new layer under it ready for colouring

Right Way – Select all the art, and copy it.
Make a new Channel. Paste art into it.
Go back to Lineart layer. Delete all art.
Go to Select>Load Selection. Click Invert. Pick Alpha 1 from dropdown.
Go to Edit>Fill, choose Black.
Lock Transparent Pixels on lineart layer
Change Image>Mode to CMYK (for print) or RGB (for screen), do not flatten layers.
Make a new layer, name it Trapping. Move it below the lineart layer.
Go to Select>Load Selection. Click Invert. Pick Alpha 1 from dropdown.
Go to Select>Modify>Contract. Use value of 1 pixel.
Go to Edit>Fill, choose Colour, use values 0%K, 60%C, 30%M, and 30%Y .
Lock the layer.
Make a new, all-white layer and place it at the bottom of the stack.

So with the artwork all prepped (either for web colours, or print colours), our next step is to start putting down flat colours on this bad boy…. But that’s another post…  HERE




2 thoughts on “Digital Comic Colouring – How I Do It, Part One: The Preamble

  1. Thank you so much for taking the time to type all this out! It’s incredibly helpful and interesting to see the different approaches and this is so thorough. So happy you did this, again thanks!

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s