While acknowledging that we can’t judge books by their covers, how much does the design of a book affect your reading enjoyment? Hardcover vs. softcover? Trade paperback vs. mass market paperback? Font? Illustrations? Etc.?
Once I'm really into the story, it doesn't matter quite so much, but of course there are preferences and pet peeves.
I'm irritated by books that. . .
- are so tightly bound that it's a huge effort to keep them opened to the right page.
- weigh so much that I grow tired just from holding them up.
- have embarrassing or hideous cover art.
- have cover art done by someone who obviously knows precious little about the story.
- try to squeeze too many words on one page (i.e. tiny font and/or insufficient margins).
- have pages that are too thin or tend to stick together.
Illustrations don't usually matter that much to me-- with three notable exceptions: 1) books intended to be accompanied by illustrations, such as children's picture books; 2) "how-to" non-fiction-- cookbooks, craft books, home improvement, gardening, etc.; and 3) books that I grew up thinking "should" be illustrated (meaning that the editions I read a a child were illustrated-- such as the Little House series as illustrated by Garth Williams).
One other thing--
Even though I do sometimes read books borrowed from a library or buy second-hand books, I'm much more comfortable with a book that is my own. With library books, I can't completely forget that they aren't mine to keep, and with any book that I didn't buy new, I guess I just feel a little twinge of "yuck" and "I wonder where has this book been and who's been pawing it with dirty hands".* (g) A little silly, maybe-- especially considering even "new" books have been touched a few times by other people. Once I've had them a while, I don't think about that so much. I don't know; I guess that they're magically rendered clean simply by virtue of spending a little time in my pristine -- ha ha ha-- home. ;o) Well, that and the fact that I give them a wipe-down.
* Hey, it's a legitimate concern! At a recent used book sale, my sister found a book with cake on it! (g) Not all book owners are so careful with their books as they ought to be. ;o)