Hi, *insert childhood adoration here* just got home from work and don't really have access to true coherent thought. Um. Okay.
Do you know why sometimes, books in a series, from the same publisher, will be in two different sizes? My sister and I figured out that sometimes the exact same book from the same publisher will have two different thicknesses of paper and so one will be slightly thicker, but we can't work out the height and width thing. Same cover design type, like, same edition. Just. One of them is bigger. Do you know why?
Thanks for the wizard books that first made friends of my cousin and me.
First: you're very welcome. I'm glad to have been of service.
On the size question, though: This is one of the Great Imponderables that drives books' writers at least as far around the bend as their readers.
Now there are some explanations that make at least some kind of sense. Sometimes, for example, even within a single edition of a single book, there may be difference-in-thickness issues for some concrete reason: the challenge is discovering which reason (assuming the publisher hasn't themselves told you about it, which is likely to be the case about 99% of the time). ...A common problem is when, for some reason to do with ongoing geopolitical crap or national/international crises, the price of paper changes suddenly. This will cause publishers to try to reduce costs on a book by (the next time it goes back to press) changing the paper quality for something thinner. One of these changes might come between volumes of a series, which is why you might suddenly get a difference between the paper quality of book 5 and book 6 of what's otherwise supposed to be a unified set.
(There's also a similar weirdness in which going up a level of paper thickness will allow your publisher to shove a book of a given length into a slightly higher price point. So, whammo, it happens, and no one bothers consulting you about this detail.)
Or alternately: All of a sudden, somebody at your publisher decides that your series needs to be packaged in a slightly different format that—for reasons that possibly no one in the field even fully understands—is becoming associated with better sales at some other publisher (or some other imprint at your own publisher). So, bang, between one book of a series and the next, the next volume to come out is a quarter inch taller or half an inch wider. And/or 15% thicker (because the pulp of the paper involved has had more air pumped into it than previously). And your books will continue to look like that until some other fad or trend at the packaging end affects them.
(Or alternately, it doesn't affect them, because your publisher's focus has changed in some inexplicable way—or the in-house accountants have crunched their numbers in some new manner—and they've decided your books aren't worth spending the format-change money on.)
(sigh) Tl:dr; There's no damn telling. (It's vanishingly rare that anybody tells us, anyway.) And I wish I had a clearer answer for you than this. Apologies. :/
