Well let's get crazy. Sometimes I need to prepare things to be printed on a printing press. If you're ever going to print on a printing press, your image needs to end up in CMYK mode. CMYK stands for cyan, magenta, yellow, and black. Those are the colors of ink used on a printing press. And if you don't convert your image some one that you give your file to is going to ultimately have to convert it to CMYK mode before it gets printed on a printing press. Because those are what the colors of ink are, you're going to use. Well, the features in Photoshop don't work as well in CMYK mode. In doing things like color correction and overall adjustments are dramatically better in RGB mode. And there is a lot of technical reasons for that. It's known as a gray balance workspace, whereas CMYK is not. But, when it comes to shadows in backgrounds, like this. Oftentimes, it's best to print those only using black ink. If I work in CMYK mode, that's easy. But what if, I like working in RGB mode and I ...
just want some how, elements to print with only black ink. Somehow I want to control that. Well usually you'd have to go to CMYK mode to control it. So, let's cheat and figure out how to make this background and the shadow print with black ink, even though we are in RGB mode. Just to show you what I'm talking about. I'm going to choose the Eyedropper tool in my Tools panel. Click and hold on it. And there's something called a Color Sampler tool. That tool allows me to click within my picture, and add a little crosshair. And I'll add two of them. And that's going to cause over here the Info panel to have some extra readouts. It tells me what that's made out of. Right now, it's made out of red, green, and blue. Red, green, and blue. If I were to switch this, I could switch it to CMYK and it'll tell me how it will be reproduced. And you see it's using every single color of ink. I want it to only print with black ink. Heck, look at this background, it wouldn't use one percent black. I want those to print with black ink only. Here's how I'm going to do it. I'm going to take those bottom two layers, those are the layers that contain the shadow and the background and I'm going to turn them into a Smart Object. So Layer, Smart Objects, Convert to Smart Object. That makes it look as if those layers have been merged together, but they just got turned into a smart object. I need to access the contents of that smart object. So, I double click on the thumbnail for that layer. And if I do, they appear as a separate document. Well, that separate document I'm going to convert to CMYK mode. And I'm not going to merge the layers when I do. Okay, whatever. Then, I'm going to use an advanced feature with layers. I'm going to take the top most layer, I'll go to the letters FX, and I'll choose Blending Options. Same screen where we got to knock out shallow and we got to those blending sliders. In there, I find check boxes, right here, that says what inks can we use. I'm going to say you can't use that, you can't use that, you can't use that, therefore, all you could use is this. And, I'm going to do the same thing for the layer below. Go to letters FX, Blending Options, and turn off cyan, magenta, yellow, so we only use black. And the only thing is were using a lot of those other inks previously. So the end results here are much lighter than they're suppose to be. So, I'll have to darken this up. Well these are solid color layers. That's what it looks like when you have these little color swatch on the left. If I just double click on that color swatch on the left, I can choose exactly how dark this is. And I'm just going to try and get it close to the same brightness as it was before. I'll do the same thing to the layer above. Double click on the left side. Just making it a little darker. Click Okay. So, now if I look in my Info panel. You see that we're working on the smart object, it thinks that the shadow area will end up printing with only black ink. And same with the background area. None of the other colors. The reason why you do that in CMYK mode for large areas that should look like they are black, is because, if magenta ink prints too heavy, this would look pink. If cyan ink prints too heavy, this is going to look blue-ish. Yellow ink prints too heavy, it's going to look yellow-ish. But, with only black ink none of that can happen. Then, I'll close this. It was a smart object, and it'll ask me, since I made changes, if I want to save it. And I'll say yes. Save. It saved it back in to this file. And, so now if I ever convert this picture to CMYK mode. Right now, before converting it to CMYK mode, it thinks both of those areas are going to use all those different colors of ink. But, after converting to CMYK mode, as long as I tell it not to merge the layers. Don't rasterize. How many times can you warn me about something, just do it. Look at those areas. They're printing with only black ink. So, there's a lot of things we can do with layers. I mean we've really only scratched the surface. I've been using Photoshop for so long, there's so much you can do, that I'm trying to give you a flavor for it. So that you can get more excited about some of these features, so maybe you'll start experimenting with some of those check boxes that I didn't use, to try and figure out what they do. And the more you can figure out the more features in Photoshop and truly understand them, the more powerful you're going to become, when you're using that tool. I tried to feed you some that I think are quite useful. But, this has been Advanced Layers, as part of Photoshop The Complete Guide.