>>1993566Depends upon the particular example.
Screen-Tone (what you are calling "grids", I think, used to be pre-printed transparencies which could be pasted down atop artwork.
The patterns could be overlaid or scraped away with an x-acto knife. Nowadays, it's mostly done in the computer.)
is difficult to seamlessly match.
For example, if you wanted to remove a speech-bubble and hide the empty space.
I've found that it's usually easiest to remove the screens entirely and re-draw from scratch.
Here's a gradient-strip followed by different methods of converting to black-and-white.
There are also specialized programs like Manga Studio, which are the same ones the authors of original mangas use today.
