Coloring a Graphic Novel – Lines on Transparency

by Jason Brubaker on May 26, 2011 at 5:00 am
Posted In: Blog, Making Graphic Novels

Most of you probably know how to use Multiply by now to color under your line layer. But what if you need to color your lines? What if you want to put your lines on a real transparency without using Multiply? Shortly after posing my tutorial on using Multiply someone suggested a different approach. It took me a while to understand how to do this but now it’s my new standard. Here it is…

How to turn your line art into a real transparent layer so you can paint line art easily while preserving all the gray value tutorial!

Is that a long enough name for yah?

Okay then, start by converting your project to grayscale like this: Image/Mode/Grayscale

Some dialogue boxes will pop up like this:

Why do this? Because in a color file you have 4 alpha channels. (RGB, Red, Green, and Blue)

When viewing a color file, all four alpha channels are turned on to see the full color range. You can access your channels by going to Windows/Channels.

When you convert your file Mode to Grayscale you will only see one channel: Gray.

Now that you only have one channel you need to select it. To do that, simply hold down Ctrl(PC) or Apple(Mac) and click on the Gray channel. (This is possible without converting your file to grayscale too. Simply select the Blue channel instead and it should do the trick. I’m just not convinced it’s as good of a selection.)

Now you should see selection lines all over your art. You have officially selected everything white. Even the small percentages of white are selected but it’s hard to tell just yet. Your line work will look something like this with the dotted lines moving around everything.

Now we need to invert our selection so that the black lines are selected instead of the white. Hit Shift+Ctrl+I (PC) or Shift+Apple+I (Mac) to invert your selection.

Now you will want to make a new layer to place your newly transparent line art.

I like to rename it “Alpha Lines” so I don’t get it confused with the flat line layer.

Make sure your new layer is selected…

Remember those lines we just selected from our gray channel? We need to fill that selection in with a black paint bucket. hit Alt+Backspace to fill in your selection… with black… if you want black lines. Or just hit it with the paint bucket tool.

Deselect your lines by hitting Ctrl+D (PC) or Apple+D (mac) and you now have a perfect transparency of your graytone art without any white.

You will want to make a new layer of solid white to put underneath your lines and you might as well just throw away the non transparent art layer too.

Now take your line art layer hit the Lock Transparent Pixels button. Presto!

You are now ready to rock! You can still paint on your lines but nothing else will get painted. Grab your paintbrush and start going buck wide and see what happens. Remember to convert your file back to RGB otherwise you will only be able to paint graytones.

Now you can paint your lines any color without getting your lines all muddy in the process and you don’t need to have your line layer set to Multiply either even though it will look identical. All the subtle transparent detail is still in the lines. There is absolutely no white value anywhere anymore.

See how easily I painted all over Victuals’ line art! Psychedelic man!

This is my new standard for preparing my files for color. Well, except for the rainbow effect. Hope it helps!

P.S. Be a dove and Tweet this tutorial if you like it!