Skinny’s got it. Whenever I’m scanning line work, I scan in grayscale @ 300 DPI slightly underexposed, then adjust the white and black points in photoshop. Usually all this involves is dragging the white slider down a little bit into the histogram and playing with the 50% one. Sometimes I’ll put a little bit of sharpening or blurring on the image (often a radius of 1 pixel or smaller) to make it pop.