Transparency

There's a nice little trick in Photoshop using the channels tab that allows any drawing to be turned 'transparent,' like an animation cel. Cel shading has been around for quite some time, and used to be hand inked and painted, frame by frame. Cels were inked first, then painted on the back, to eliminate brush strokes from the finished cel. Each one became one frame of the animation. Through the years cel creation became more and more efficient, especially once Xerography was invented, which allowed drawings to be transferred directly onto the clear plastic, rather than having to trace every single one from the original drawing. This process was tested on Sleeping Beauty, and the entire film of 101 Dalmatians was made using this method (which gives it its charming, sketchy look. There's more potential to this though than just cel animation.

Classical, a user on DeviantArt, used this transparency technique on That Sinking Feeling. You can see the black and white line art here.

It's also a great way to color that amazing drawing you did(Thank you TracyJB), add some tone to it, and stop relying on the 'multiply' setting.

I've used this technique before, but thought I'd experiment a little more than usual with it, and tried this little picture, which turned out looking pseudo silk-screened, but which I actually think would probably be a silk screening nightmare.