Easy-to-follow video tutorials help you learn software, creative, and business skills.Become a member
In this exercise, I'll introduce you to the final color mode that's available to you inside Photoshop, which is CMYK. Now those letters CMYK stand for Cyan, Magenta, Yellow, and Black. The four so-called process color inks, which are the standards for commercial printing. And the reason I bring up CMYK in the first place is because one of the most common questions I get when I'm showing folks how to mask images is can I work in CMYK? Because between you and me I personally do 99% of my work in RGB, I do a little work occasionally in lab, and I do exactly 0 in CMYK.
And I'm about to show you why? And over time I'll show you tips and tricks for grabbing mask from an RGB image, but I want you to understand why masking from CMYK is generally a bad idea. I've gone ahead and saved my most recent version of that original composition as Crazy RGB colors.psd. I'm going to go ahead and turn off that Vibrance layer, because we don't need it, and then I'll go out to the Image menu choose mode and choose CMYK Color. Now notice I didn't duplicate the image this time.
If I was really making a conversion that I cared about, I definitely would, because converting from RGB to CMYK is about the most destructive color conversion imaginable. So you definitely would not want to save over your original RGB image, but I've already created an alternate version of the image that we'll be using throughout this exercise. I'm just demonstrating how you get there for now. So you choose CMYK color Photoshop tells you that it's going to throw away the adjustment layers. I'm going to say OK, because there is really no advantage for flattening this image.
It's not going to look any better, for example,. So I'll click OK to move on then Photoshop tells me hey, you're going to convert to the CMYK profile that you established in the color settings dialog box, which by default here in the States is U.S. Web Coated (SWOP) v2. Well, that's just fine by me, so I'll click OK. Notice how dramatically those color shifted. So this is before, now this is brightly saturated greens, those red shades of violet and blue in the background, and this is after, with these dramatically diminished colors, as a result of our conversion.
Well, that's just the way it is with CMYK, of all the color modes we've seen, CMYK has the smallest gamut. Meaning that it's capable of representing the smallest group of colors. But in addition to converting our background photograph, I also went and converted the color swatches, which is why I've created an alternate version of the image here, it's called The CMYK toucan.psd and you'll notice that the swatches look different. In particular, we'll go ahead and select this Magenta swatch. Check out what the magenta swatch looks like when we converted from RGB to CMYK.
It looks pretty purplish, and then here is my modified version of that magenta swatch rendered in true CMYK magenta. Just so that you have a sense of what's going on. All right now I'm going to go ahead and switch over to the Channels panel, notice that we have a CMYK composite view of the image at the top of the stack, and then we have our independent color channels, one each for the printing plates, that is the Cyan, Magenta, Yellow, and Black plates that are necessary to reproduce the full-color image. Let's go ahead and see those channels and color by pressing Ctrl+K Command+K on the Mac to bring up the Preferences dialog box.
I'll switch to Interface; I'll turn on Show Channels in Color and click OK. Now you can see what these colors look like. The assumption is that you'll be printing the white paper, so the brightest color is white and the darkest color is the color of the ink, in this case Cyan. If we move to Magenta, the brightest colors is white, the darkest color is the ink Magenta. Same with Yellow, and bare in mind that yellow is the color complement to RGB's blue, and so not surprisingly, it's very difficult to make out what's going on inside this channel when it's depicted in color.
And then finally we have Black, which is the stabilizing ingredient that holds down the shadows inside the image. All right, I'm going to go ahead and return to the Cyan channel for a moment here, so that I can show you that I've set up the same image using layers, just as I did for the RGB demo, and that demo file is called CMYK revealed.psd. I'll go ahead and switch over to the Layers panel, and then I'll turn on the Magenta layer, click on it, and this time as opposed to choosing the Lighten mode, as we did when working inside that RGB demo, I'll choose the Darken mode.
Because after all each channel darkens the others. So I'm going to choose darken and that creates a mixture of the Magenta and Cyan inks. Now I'll click on Yellow, turn it on, change it to Darken as well, and now you have a sense of what all the channels look like before we add black. And finally, I'll click on the Black layer, turn it on and change its blend mode to Darken as well, and we get that full-color CMYK depiction of the image. And notice now, if I switch back to the authentic CMYK version of the image, switch back to the Channels panel, and click on CMYK, that I get the same result.
So there is the demo file and here is the actual CMYK image with all four channels intact. So I just want to give you the sense that the channels are darkening each other as opposed to lightning each other, the way we saw with RGB. Here is the problem though; I'll press Ctrl+K or Command+K on the Mac to once again bring up the Preferences dialog box. Click on Interface, turn off Show Channels in Color, click OK. Let's take a look at those various versions of the image, they're all bad, is the problem.
There is the Cyan version of the image, there is Magenta, there is Yellow, I might be able to mask this particular image with some success using that Yellow channel, but it's still in pretty bad shape, some very jagged transitions that we don't see in RGB. And then finally the Black channel is as usual, utterly useless to us. So just trying to give you a sense, it's a bit of an exaggeration to say that you absolutely can't mask in CMYK, but you're better off doing so in RGB.
And what I generally do, when I'm working with the CMYK image is I'll go ahead and Duplicate that image and then after I get done creating the duplicate, I'll convert the image to RGB. It won't look any better. You're not going to restore the lackluster colors, but you will be working in the RGB mode and those channels will be in much better shape. I might as well go ahead and show that to you. In fact, I'll go ahead and flatten this version of the image, so we can see, here is the Red version of the image, here is the Green version, and here is the Blue all unique and recognizable depictions of that full-color Toucan and they would all be useful for creating the mask.
And by virtue of the fact that you had a duplicate file that was in RGB, you could create your masks and transfer them over to the CMYK version of the image and then apply those masks as desired. And as I say, we'll be seeing how that works in future chapters. All right, so that's how things work in CMYK. In the next exercise, I'll introduce you to a mode that's not even a color mode, called multichannel.
Get unlimited access to all courses for just $25/month.Become a member
120 Video lessons · 57821 Viewers
119 Video lessons · 67324 Viewers
84 Video lessons · 16679 Viewers
125 Video lessons · 29565 Viewers
Access exercise files from a button right under the course name.
Search within course videos and transcripts, and jump right to the results.
Remove icons showing you already watched videos if you want to start over.
Make the video wide, narrow, full-screen, or pop the player out of the page into its own window.
Click on text in the transcript to jump to that spot in the video. As the video plays, the relevant spot in the transcript will be highlighted.