Wow! Elizabeth Bluemle, who writes Shelf Talker: A Children's Bookseller's Blog for Publishers Weekly, has really outdone herself with the 03/04/10 post about "Strong Spines." The many photos posted on that page show book after book (many ARC's) on her "To-Be-Read" shelves at home, and they speak clearly to the importance of colors and typography choices in the under-discussed area of book spines.
As Bluemle points out, not every book is going to be placed face out on a bookstore shelf (hopefully, we're still thinking of bookstores when we think about a book's presentation, not just online cyber-presentation.) There's just not enough room for all the books to get that kind of shelf space.
Though Jacket Knack's usual focus is the front cover of a book, the full spread (including flaps, backs, fronts and spines) is important. One example that got talked about this last year was the cover for Jerry Pinkney's Lion and the Mouse, which features the Lion on the front, and wraps around to the back to show the little mouse. But picture books don't have enough room to do much on the spine.
Not so with longer fiction. Spines present all kinds of opportunities IF the length of the book is sufficient to give a book designer space to be playful and/or just plain smart about catching a reader's attention. I have a book of poetry on my shelf which has such a striking spine that it actually gives me the creeps, because it is so wide it allows for half of the photo of the poet (James Merrill) to wrap across the spine from the front of the book. I can't find a photo of the spine online, but here is the front cover. The book is a hefty 885 pages, which makes the spine about three inches across You can imagine what the rest of Merrill's face looks like, staring at me from the bookshelf. I honestly can't have it standing upright on the shelf - his eye follows me around the room - I have to lay the book down on its side.
The books Bluemle talks about at PW are not quite this thick nor quite this innovative (nor, I think, are they as unnerving.) She offers about half a dozen easy pointers about what catches a customer's eye (some of them very basic, such as high contrast and LARGE FONT!) A title written in cursive is extremely difficult to read when running vertically down a spine - I'd never thought of that before. Small images turn muddy and indecipherable from the two-foot distance most customer's stand at when browsing a bookstore shelf. Metallic inks (such as the kind used on BEAUTIFUL CREATURES by Kami Garcia and Margaret Stohl) are often hard to see unless light shines directly on them. Here are two photos from Bluemle's post (the first taken with a flash, the second without) which clearly show how hard it is to see the title of BEAUTIFUL CREATURES without direct light shining on it (the second photo has a slightly different center point, and BEAUTIFUL CREATURES is farther to the right)
Definitely check out the post over at PW. It's so clear, from the photos, how important an easily readable spine is. The trick for the book designer is how to make something both readable AND intriguing.