A book’s index is an afterthought for most publishers—allocated the pages that are left over from the last signature after the main body has been set. What ends up happening (entirely too frequently) is that indexers are handcuffed by a severe lack of space. I once had to compile a six-page index to a 336-page book—that’s less than 1.8 per cent of the page count—and I was forced to trim so many entries that the index was, for all intents and purposes, useless.
For a reference books or technical manual, the index can be one of the most important components of the publication, and most of the indexers that I know charge by the indexable page rather than the entry, so they’d be charging the same total fee regardless of index length. To severely limit the index space would hurt the book more than it would the indexer (although I’d like to think that most indexers would be disappointed to put forth an inferior product).
What we need, then, is—dare I say it?—a paradigm shift. Publishers and editors and whoever has input into the total extent of a book needs to consider the index integral from the outset. Do a rough cast-off based on the manuscript, and if what’s left over of the last signature is less than, say, 2.5 per cent, consider adding another half or full signature, depending on the total length of the book, and use this new page count in your project budget and P&L.
The American Society for Indexing has some guidelines for index lengths. For trade books, indexes should be about 3 percent of the book, whereas for technical reference books, they could be up to 15 or 20 percent. These figures can be squeezed a little bit, especially if you’re reducing type size in the index, but they shouldn’t be significantly less than what the ASI has recommended, if you want the index to be functional and readable.
On the other end of the spectrum are self-publishing authors or publishers who don’t give any index specs at all and say, “I’ll just do what I need to do to make your index fit.” This scenario is cropping up more frequently as more people are turning to print-on-demand options where they can add pages two at a time rather than worry about a full sig. It sounds like an indexer’s dream, but, in reality, we appreciate constraints. Without a size limit on the index, the temptation to hand over a bloated, unedited draft is entirely too high. Having index specs helps indexers trim the fat—to put careful thought into clear and concise subentries and eliminate redundancies that can lead to clutter.
Basically what I’m saying is that indexers are a lot like chickens (an analogy I’m sure you’ll hear no other indexer repeat). We’re happiest—and we produce the best product—when we’ve got space to roam around and breathe fresh air. But we also understand the need to be penned in, for our own protection. And, of course, getting a generous amount of feed for our troubles doesn’t hurt, either.