Okay, as an illustrator, I frequently find myself needing to remove all white from a layer in Photoshop. I’ve been doing this with a filter called Kill White which I talked about here. But I always thought this was such an obvious need, why doesn’t Photoshop come with a tool that does this already? Something in their filters or maybe in Image->Adjust? But I’d never found it.
Now, of course, had I taken any formal Photoshop classes I might have learned the trick from a professor. But as it is I learned Photoshop on-the-job, on my own, and from the occasional online tutorial. So, although I’m well-versed in the day-to-day operation of Photoshop (and even many obscure things that it can do) I do have the odd hole in my skill set.
Well, a few weeks ago I filled one of these holes. I found how you properly remove white from a layer. Without any add-on filters. I’m sorry I can’t cite my source. I think I saw the explanation on tumblr. But I’m really not sure where. But whoever the mysterious educator was, you have my gratitude.
Anyhow, here’s what you do. (And it’s stupid easy, btw.) You know that CHANNELS tab you probably never use and have no idea what it does besides change your image funny colors when you hide one channel or another? Well, it uses that. If you don’t know what I’m talking about, go to the Window menu and go down to Channels. Click that.
Now you see it? Okay, good. Remember where it is, but go over to layers tab for the moment. Choose the layer you want to remove white from. Make sure it isn’t the background layer. If it is, copy or convert it to a regular layer. Select that layer.
Now go back to channels. All four channels are selected. Leave that as it is. Look at the bottom of the channel window. There’s a line of symbols. A dotted circle (Load channel as selection), square with a circle in the middle of it (Save selection as channel), rectangle with the corner folded over that means new (Create new channel), and the trash can (Delete selected channel). So, that first symbol is the one that matters. The load channel as selection. With all four channels selected (as they were when you got there) click that dotted circle.
That automatically selects all the white in the layer. Not just all the white, but if the pixel is 20% white and the rest some color, it is selecting that 20% white but not the 80% color. Don’t ask me how it does that, just accept it. So, now, while all the white in your image is selected, press your delete key.
Now click Select->Deselect.
And you’re done. Your white is gone leaving only your lines.
Can’t see it? Add a new layer under the one you were working with and fill it with white. See it now? Good. 🙂
One more fun thing. If you wanted to tint or monochrome all the lines, this is a really good time. Or if the lines seem too light to you after removing the white. So, go reselect all the transparent stuff that used to be white before you deleted it. Do this by clicking Select->Reselect. Then click Select->Inverse.
Now all the stuff that is not white is selected. And selected so that the 20% transparency on the pixel (previously 20% white) is not selected, only the colored 80% of that pixel. So, if you want, just paint over that layer with a big brush of whatever darkish color you want.
There you go.
I guess I really should take the time to learn what else the Channels tool actually does, huh?