Join Claudia McCue for an in-depth discussion in this video Creating a simple spot color channel, part of Print Production: Spot Colors and Varnish.
I'm starting with this nice, color image, but I'm going to use it on a project that's just printing in two colors, a Pantone 354 green, and black. So, I want to do something sort of interesting to him. I don't want to use just a standard duotone. I want to make sort of an interesting effect, where I have a solid hit of that spot color right where his shirt is. So, I need to do a couple things to prepare for that. First of all I have to start by making my gray scale image. And I'm going to use that nice black and white adjustment. Now, a little tip, if you want to use that black and white adjustment you have to start with an RGB image.
You'll find that adjustment isn't available if you start with a CMYK image. So, if that's what you have, you'll have to convert it to RGB first, and then you can do it. So I have an RGB image, I'm going to use my Adjustment layer, and I'm actually going to lighten up a little bit, and then I'm going to come back and do a local correction to the shirt. So remember, I still have a color image, even though it looks gray scale, it's really still an RGB image. You can see those channels are still here, in the Channels panel. So first you need to make it an official gray scale image, by going to Image > Mode and Grayscale, and then Photoshop's going to warn me that I need to flatten in order to exercise that adjustment, so I will flatten. And of course if you get tired of seeing these you can always check that Don't Show Again box.
Now I have a good old fashioned gray scale image. But I want to pump up the dark parts of this shirt, so that I sort of accentuate the creases and I want to lighted the lighter parts and the mid tones, in order to leave room for that green that's going to come in on top of it. Otherwise it looks a little bit heavy. So, sort of like a cooking show, I happen to have a mask, and I'm going to use that. So, I'm going to go to Select and Load Selection, and I'm going to use that shirtmask. And, I think for this I'll just use Levels. I'm going to drag this little midpoint slider a little bit to lighten up the midtones.
Remember, it's just happening to the shirt. See, it's just the shirt that's being affected because of that active selection, I'm going to add a little bit of white by dragging the black point slider. This is a fairly heavy green, so we want that shirt to be able to sort of fight back, and I'm going to lighten up the lighter ends. You don't want to really get rid of everything, I just want to lighten things up. So, when I close properties, if I turn that Adjustment layer off and on, you can see that I've lightened up the shirt, but I haven't gotten rid of the content of it, I still have some gradation. To do what I want to do next, I'm going to flatten this. So, I can choose either Merge Down or Flatten, either choice is going to really result the same.
Now I need to make my Spot Channel. Now I have two channels already in this image. But they're Alpha Channels, they're just places to store mask. What I need is a special kind of channel which is a dedicated Spot Channel. So, in the Channel's Panel Menu I just choose New Spot Channel. When I click color, it thinks I want to pick something out of the picker. But I don't, I want an official Pantone color. So, when I go to Color Libraries, I can choose the correct color. I want to choose Pantone 354, so I'm just going to type 354 really fast, there we go.
When I click OK. I now have my new spot channel, but again, it has nothing in it to begin with, so I need to populate it. Now this going to be a solid hit of that Pantone 354, so what needs to happen in this channel is I need to have a solid fill of black to represent that solid fill of ink that's going to print. So I'm going to use my shirtmask. Now here's another way to load a selection; this is actually my favorite way. If you'll just drag it down to this first little icon, which is, make a selection, there you go, there are my marching ants. Now I want to fill this with black.
So if I, were to change my background color to black an hit Delete you would think that would happen. when I hit Delete, I get the content aware fill. Well actually the fill dialog remembers the last choice you made, but the default is content aware. Oh, that's not what I want. Well, I could choose black. Frankly, that's the long way around. Let me show you a little trick that I like of course, it's up to you to do it however you want. What I like to do is use a keyboard shortcut to do this. So, if I switch my foreground and background colors, then I can hit Opt+delete or Alt+delete. And that's the short cut for fill with foreground colors. That's my solution, just swap them, so that I have black as my foreground color, hit Opt or Alt+delete and there we go.
A little faster then writing out that dialog. So, remember I specified this is Pantone 354, when I turn the gray channel back on, this is how it's going to print. Pretty cool, huh? So, this is the only way to control exactly where spot colors are going to fall in a multicolor image. You can't do it with a standard duotone, you have to do it manually, like this. The one other thing I wanted to do, of course, was separate him from the background. So, to do that I could just bleach out the background, but what if I wanted to put him in on top of something else when I wanted to show behind him.
Well then I would just have opaque white, so that's not what I want. First of all, to get rid of my shirtmask just to make the file a little bit smaller. Generally speaking I keeps those things around until the last minute, but I think I'm going to be okay here. If I want to silhouette him, I can't do that with this background layer. The reason is that a background layer is sort of glued to the ground, it can't have transparency. So, this needs to be a floating layer, before I can mask it off, so that he's just floating in empty space. So, first thing I'm going to do is, I'm going to load the Selection. That is this knock out selection that I'd already make. So, it's a channel that already exists near my marching ants. In order to mask this, I need to convert this to a floating layer. All you have to do is double-click on that background, and of course you can give it a name if you want.
I'm just going to leave it at Layer 0, and click OK. And now at the bottom of the Layers panel, I'm going to choose Add Layer Mask. And there we go. And that gingham, of course, is how Photoshop shows you that this is transparent. So, now I can save this image just as it is, it's going to print in two colors. And I can put it into Illustrator or into InDesign. And he's going to be floating on empty space. It's all going to be transparent behind him, and that way anything that's behind him is going to show around him. So, remember how we got here, started with my color RGB image, used the black and white adjustment in order to convert it to a little bit better gray scale. Need a spot color channel, and then fill that area of his shirt using a mask in order to apply that spot color green just there.
So it's really not that hard once you do it once or twice, and sometimes it's just a little more interesting result than just making a standard duotone.
- Why spot colors are necessary
- Making a decision between spot and process colors
- Choosing a spot color
- Understanding the effects of stock on color
- Printing spot colors digitally
- Using varnishes
- Creating a multi-tone image in Photoshop
- Adding Pantone color swatches to Illustrator
- Creating spot varnishes in Photoshop, Illustrator, and InDesign
- Using preflight profiles in Acrobat