ah okay, grahamgg was talking about the Artist select ones. Artist editions (other publishers call them Gallery editions) are reprints of the original pages, inked but not colored, high resolution scans on the same type of paper the artist used and in most cases in the same size (so the books are huge). They really feel like someone bound the original art pages into a book. Every smudge, erased line, whiteout fluid is visible.
There are also Artifact editions which are basically the same but they collect select pages from runs and not full issues.
Also IDW never includes digital lettering on their pages so if it's a never series like the Mignola AEs that were lettered digitally they don't have any text in them. In case of older books the lettering was done by hand so the book is fully readable.
This website has a ton of reviews and pics:
https://aeindex.org/category/reviews/