Scanned line art is a 1-bit bitmap graphic. The quality of the printed graphic depends on its resolution.
Line art is a black and white graphic that consists only of solid lines, like a pen and ink drawing. Line art can be either a vector graphic or a bitmap graphic. If vector, you don't need to make any other consideration than you would for other vector graphics. However, if the line art is a bitmap, you have to make sure its effective resolution is high enough to avoid jagged edges.
Unlike other bitmap images, bitmap line art is not converted to a halftone.
The imagesetters used by your commercial printer print at resolutions of 1200 dpi or higher. This means that each mark the imagesetter makes on the film is a square that is 1/1200th of an inch or smaller. A scanned image comprises a finite number of pixels.