Creating a multitone image (duotone and tritone)

I'm working on a project that's going to print in two colors. …Pantone 185 which is a red and process black. …So, because I want my images to look a little bit more interesting, I'm going to …turn them into duotones. So, here's the finished product, and I …want to show you how you get from point A to point B. …An interesting thing to know about duotones is that under the hood, they are …really grayscale images. I'll show you why. …A duotone is really, under the hood, still the original grayscale image with some …instructions attached that tell the output device what to do.…

So, my grayscale plus the duotone settings that I add to it, become a …duotone, the output device a plate setter, understands that it's going to …generate two inks, one for the black and one for the Pantone 185. …And you'll notice, this is kind of interesting, the file size really doesn't …change much. So, the original image is 1.7 megabytes. …The duotone is 1.8, and that little extra is because of those settings that are …