If their content weren't NC-17, they could be drawn by small children, which makes them look all the more unsuitable as erotic art. I'll say up front that some of the illustrations that artists post are plain bad. What a wide variety there is in levels of expertise! And how different are the graphic styles that influence fan artists.
I found it very educational (and, in the end, inspiring). I don't mean manips, but paintings and drawings. Recently, following links to links, I have been browsing LJ's and galleries for LotR fan art, specifically erotic art featuring Frodo. Warning: Adult content (discussion of LotR erotic fan art, although not at all graphically).
