Cool Trick with White Line Art (For Beginners)

I was thinking about this today, and I tested out my theory and it worked! I'm probably not the first to figure this out, but at least you guys learn something This would look awesome if the lines were smoother and thicker.

I made another tutorial about how to color line art with a white background. [link]

I DID NOT MAKE THE LINE ART.

SeeU Line Art: [link]
Hatsune Miku Line Art: [link]