316 Pay attention to Transparency Blend Space

- [Instructor] I want to talk about a kind of obscure feature in InDesign, something that turns out to be really important, especially when printing from InDesign, but that most InDesign users don't even know about. It's called Transparency Blend Space and it lives here at the bottom of the Edit menu, way down here and you can see that there are two options, Document RGB and Document CMYK. Now, most of the time you'll find this set to CMYK, which is fine if you're going to be printing your document on a printing press, like a commercial printer.

But there are two times when you should change this to RGB. But before I tell you about that, let me quickly explain what the Transparency Blend Space thing does. Okay, you know that you can combine RGB and CMYK images and artwork on the same page in InDesign, right? But here's the thing, as soon as you have any transparency on the page, like a drop shadow or an image that has a transparent background, or anything like that, as soon as there's transparency, InDesign has to convert everything to either CMYK or RGB.

It just has to for technical reasons. And that's why sometimes you'll see a whole bunch of colors or gray scale images just change suddenly on your page. Like, check this out. I'm going to select this pink box, the magenta box there, and I'm going to go to the control panel and I'm simply going to click on the drop shadow button up here just to give it a drop shadow. And as soon as I do, did you see that? Did you see all of those colors change? It shifted, many of them became more muted. Sometimes you'll add an effect or just import an image and all of a sudden, all the colors on a spread will change just like this.

That's the Transparency Blend Space kicking in. Okay, like I said, there are two times to change the Transparency Blend Space to RGB. First, change it if you're working on an interactive document, something that will mostly be read on screen. For example, maybe you're going to be exporting a catalog or a product sheet for your company and you're putting it on your website and most people are going to download it and read it on their computer screen. Yeah, maybe they'll print it out on their own desktop printer, but in general, they're mostly reading it on screen.

In that case, use Document RGB. Look at that. I selected Document RGB and all those colors went back to the way they were before I added that drop shadow. Much better, right? Okay, the second time that you want to use RGB is if you're going to be printing the file, but the final print is going to be on a desktop printer, like an inkjet or a color laser printer. In that case, once again, you want to use Document RGB. Yeah, I know those printers use CMYK ink or toner or cartridges, but trust me, unless you have a really high-end printer, it probably is designed to be treated like an RGB device.

I talk about this in much more detail in my course, InDesign: Color Management. So like I said, Transparency Blend Space is kind of obscure, it's a little technical, but if you just pay a little attention and follow those rules, you're going to end up with much better looking output.