I can't help it! I love the effect the old toning art supply Zip-A-Tone/Letratone/Chartpak/Letraset gives and always have. Just that old, 50's clipart look.
When I worked at an art supply store many years ago, I went on an epic hunt for the stuff and emailed and called about a dozen art supply distributors who all told me I was out of luck. No one made the stuff anymore, since Photoshop did such a better job of toning and printing technology had advanced a great deal since it was popular. It was only when I spoke with a youngish silk screener who knew that in some areas of Japan they still make the wonderful tool that the trail grew hotter. Well, as luck would have it, after a few months, I finally got my hand on some (and some great Japanese self-inking brush pens that I still use a lot!) and have just about run out, almost ten years later. I'll admit, I was conserving it, but to be honest, what for? Since then, I've learned how to simulate it in (guess what) Photoshop and can print my own sheets of it whenever I want. It's fun breaking out the x-acto knife and playing around with it. I guess I've always had an abiding respect for the old ways and always will.