Digitally restoring comics is one of my hobbies. Why? Well, you might want to use a nifty Kirby drawing of Silver Surfer as a computer wallpaper, or print the restored page and insert it in the original damaged comics; maybe recolor it as you like and print a poster out of it. But my main reason is because is fun and relaxing: I mostly work on Kirby comics, and I like looking at the small details of his pencils.
So let’s start with the very basics.
We need a comic book page asking for digital restoration, a scanner, a computer and a photo editing program (I will use Photoshop)
Digitize the page
The first step is, of course, digitizing the page (or the cover) of the comic book that you intend to restore to its original beauty.
Position the comic book on the scanner so that it is as flat as possible. Scanners (mine is an old Epson) usually come equipped with some editing software. However I prefer to acquire the page raw, with no adjustments from the scanner, and use Photoshop to do all the editing.
In order to be able to recover and restore even small details of the drawing it is important to scan the page at a suitable resolution. 300 dpi is the bare minimum but I recommend at least 600 dpi. 1200 dpi would be the best, but editing 1200 dpi scanned pages requires a lot of RAM and your computer might be too slow (mine is).
Look at this picture (Fantastic Four v1 #55 page 3 panel 2, here you see the Italian reprint in Fantastici Quattro #51).
It has been scanned at 150 dpi.
It might look good on the screen, but if you enlarge it you will see that many details of the original art have been lost and the edges are jagged.
This resolution, typical of many scanned comics you can find on the web, it is ok if you just want to read a digital version of a comic book, but it is insufficient if you want to do some serious editing.
Now look at the details above the eye on the right, scanned at 300 dpi
As I said scanning at 300 dpi is the bare minimum. You will be able to do some editing, mainly retouching colors or clear some stain, but it will be difficult to do more advanced stuff such as extract the blacks and recolor the picture, since many details of the black ink have been lost.
600 dpi is a good compromise between file size, memory requirement and quality of the picture
Scanning at 1200 dpi is however recommended if you want to print a larger version of the scanned art
Saving the page
After scanning the page save it without retouching. I prefer to use a different directory for each project. The best thing to do is to use a lossless format, like .psd (the native Photoshop format). Beware that lossless formats usually generate big files. In case you prefer to use the more common .jpg, which is a lossy format, save at least at quality 10.
In case you don’t know what a lossy format is, the picture is compressed in a way that not all the pixels received from the scanner are saved with the original color. Some information is discarded in order to reduce the size of the file.