About the Size of It
Book Trim Sizes Explained
Hi and welcome to Shelf Life where your editor friend Catherine scours the far reaches of the internet to find the writing, editing, and publishing questions you would be dying to know the answers to if you only knew to ask them. In Tuesday’s article I talked about just deleting social media if you need a break from it. I have deleted Facebook, which has been liberating. I’m still on Twitter because—now I no longer have Facebook writing groups to peruse—it’s one of the places I find writers asking questions that I can answer. I’m also still on Instagram, primarily for the purpose of finding things to buy that I definitely do not need and don’t even really want.
Someone on the internet the other day asked an editor what the significance is behind different book trim sizes, and who chooses them, and for the love of dog why aren’t they all the same? And the person they asked, not being a production person, didn’t actually know, and I didn’t butt in because I wasn’t asked, but also in my heart I was like, “Ooh, call on me. Me. I know this one. Ask me.”
Hence today’s Shelf Life is all about book trim sizes and:
What trim size means;
Who chooses a book’s trim size;
What factors go into that choice; and
Why one trim size might be better than another depending upon the book.
(And maybe some other related stuff TBD.) This article may be helpful for self-publishing authors who—if a print edition of their book is in the offing—will be asked to select a trim size from a list of trim sizes and should come to that choice prepared. Hopefully, also, people who are not in the position of having to choose a trim size for a book will find it academically interesting.
Trim size refers to the height and width of a book, as measured from the spine to the free edge left to right, and from the bottom of the cover to the top. The depth of the book—that is, the bulk of the spine—is not part of the trim size. When a book is printed, the pages that come off the printing press are larger than the final dimensions of the book. When the book has been assembled—the book block bound and glued (or sewn) into the cover—then the book is trimmed down to its final size: the trim size (ta da!). The spine bulk is determined by how many pages are in the book and the weight of the paper stock used for printing and, sometimes a little tiny bit, the type of binding. The spine size is not determined by the trimming process.
I hope you like this picture. I made it in Canva in five minutes. Digital illustration is my passion.
Books can be trimmed to just about any size, but not all trim sizes are created equal. A handful of sizes are used a lot more frequently than all the rest, and those sizes are the cheapest ones to print. Standard, common sizes are cheaper to print than unusual trim sizes because when the good people at the printing operation can dedicate a press—or two, or three, or however many—to just one trim size and they don’t have to make adjustments between printing projects, they’re more efficient.
I once visited a press operation that had an airplane-hangar-sized room with digital presses lined up the whole way down it. Dozens of printing presses in that one room. Every press in that room was set up to print either 6” x 9” or 7” x 10” books. No other trim sizes. Each press was also set up to feed 50# natural paper or 60# white paper. No other paper stocks. If you were printing a book at this facility your choices were, therefore:
6x9 on 50# nat
7x10 on 50# nat
6x9 on 60# white
7x10 on 60# white
And that’s it. This was a very efficient and cost-effective printing operation because they didn’t have to account for the possibility of, for instance, 10 different trim sizes and 10 different paper stocks creating 100 possible combinations of paper and trim size.1 You’d have to have 25 times as many printing presses and none of those presses would be likely to do the same volume of books.
The lower cost of these most common trim sizes is circular. They’re cheaper because they’re the ones printed most often. They’re the ones printed most often because they’re cheaper. Ouroboros.
Who chooses the trim size of a book? If you’re self-publishing a print edition, you do. Note that you will need to choose your trim size before page composition and cover design, because the trim size determines the file setup for those. You can’t print a 7-inch-wide by 10-inch-tall text block on paper that is 4¼ inches wide by 7 inches tall. When the knives come down to trim your book block, text gets cut off. Literally.
I know that sounds obvious but I have encountered authors who simply did not and could (or would) not understand that we cannot enlarge the text block (area of the page on which text is printed) to a size that is larger than the book’s trim.
At a publishing company, in my experience, the acquisitions editor typically selects the book’s trim size, at least initially. Their choice is based on:
What trim sizes are available to me, according to the production division?
What trim size is most common for this type of book?
What trim size do the competing titles use?
Their choice for the book’s trim size will go to the publishing committee along with all the other specs they’ve chosen for the book, the preliminary P&L (or margin) they’ve calculated for the book, and all the other information the pub committee needs to decide whether or not to publish that book. During pub committee, the trim size may change based on recommendations from other folks like marketing, sales, and production.
For instance—big for instance, I haven’t priced any of this stuff in a long time so I’m making example arguments—an acquisitions editor comes to pub committee and tells us they want to do a 5⅜” x 9¼” trim size with a gatefold paperback cover and deckled edges, because the book they want to compete with over at HarperCollins has those things. I might then, as the production representative in pub committee, step in and say: “Okay we can do all that but if you go with 6” x 9” instead of 5⅜” x 9¼”, the whole shebang is 10 percent cheaper to manufacture.” And then the AE says, “but we don’t want 6” x 9”, we want 5⅜” x 9¼” like the HarperCollins book.” And then the editorial director steps in and says, “Unless you can find a way to deliver 10 percent more first-year revenue than what you’ve calculated on your P&L, you’re going to settle for a 6” x 9” trim.”
In other words, is ⅝” difference in trim size going sell 10 percent more units than if you printed at the more standard trim size? Or can you support a 10-percent-higher list price for the book based on the trim-size difference? Sales is sitting at the back of the meeting room eating a fancy salad and shaking their head “no.”
Sometimes the answer is yes and then we do the thing. Mostly the answer is no.
Other than cost, what are some reasons you might choose one trim size over another? Well, all else being equal (word count and font/leading size), a book with a smaller trim size will have more pages than the same book with a larger trim size. Larger trim size equals larger book block equals more words on each page equals fewer pages.
Production can only increase font and leading size so much to plump up a book’s page count before the effect makes the book look like it’s for kids; and conversely we can only decrease font and leading so much to shrink page count before the text becomes uncomfortable to read. Trim size is a tool in our kit for controlling page count.
By this logic, wouldn’t it be cheapest to print the largest book you can so you have the fewest pages and therefore the lowest printing cost? First, not all the cost is determined by page count and larger trim sizes can be more expensive to print than smaller ones, especially if you go above what are “standard” sizes. Second, nobody wants to read a novel that is printed that large because—let me take a deep breath.
The larger the trim size, the larger the book block, the longer the measure of the text—meaning, physically, the length of each line of text. During sustained periods of reading (like reading fiction), the human eye doesn’t want to go much longer than 3.5 to 4 inches before moving down to the next line. If you have an 8.5-inch-wide trim size, then you have probably a 7.5-inch-wide area to place your text block, which means you’re going to have:
Very long lines of text that are uncomfortable to read; or
A lot of white space around the edge of the text block; or
Multiple text columns.
None of these are good options. That’s why you don’t want to print your novel—and publishers aren’t out here printing novels—at large trim sizes to reduce page count to save money.
There are two super-common trim sizes for fiction:
4.25” x 6.75” for mass-market paperbacks (think science fiction, fantasy, or romance novels); and
6” x 9” for trade paperbacks and hardcovers.
If you have examples of both of those handy, take a look inside just to notice that the type and leading size in the mass market paperback is probably much smaller than that in the trade paperback, and the mass market paperback probably has thinner, cheaper-feeling paper. This is because, on the whole, around the same amount of text fits in a mass-market paperback or a trade paperback of the same spine bulk. (It’s not a perfect science or exact match but it’s meant to be close.)
The 6” x 9” trim size is the most common one printed in the United States, with several similar sizes grouped around that (5.5” x 8.5”; 7” x 10”; 4” x 7”; 4.25” x 6.75”) being also extremely popular and, therefore, both familiar to readers and inexpensive to manufacture. If you want your book to look like it belongs on the same shelf with its fellows and you want to keep manufacturing costs down, those are all excellent trim sizes to choose for a novel, novella, or short story collection.
If you want your book to stand out from its shelfmates, and you don’t mind paying higher unit manufacturing costs, you can print bigger, smaller, or to different proportions—for instance, square instead of rectangle shape.
Another drawback, besides higher manufacturing costs, is that your book may not look like the type of book it is, which can cause readers to overlook it in a physical setting. For instance, if you print a larger and more-square trim size that makes your book look and feel like a textbook, a reader browsing for novels might not realize yours is one.
Unusual trim sizes can work in your favor if your book’s theme supports it. Off the top of my head I’m thinking of a book I used to have that was made to look like a travel guide, so it was trimmed to the same proportions as you’d expect to see like a Michelin Guide or something like that, but it was a sci fi or fantasy fiction project that was a guide to surviving the apocalypse or something.
If you’re choosing your own trim size, I want to reiterate that you should choose this early—before attempting to lay out your text in the final, print-ready format (or hiring someone to do so) and before designing (or hiring someone to design) your cover. You need the trim size to figure out how big to make your text block and the dimensions of your cover. Also, the cover can’t be completed without knowing how many pages you will have (based on the trim size), to determine the final spine bulk.
The best choice of trim size for your book will likely be the one that:
Matches, or is at least close to, the trim size of your comp titles; and
Keeps your page count in line with those of your comp titles; and
Is most cost effective.
If you have questions that you'd like to see answered in Shelf Life, ideas for topics that you'd like to explore, or feedback on the newsletter, please feel free to contact me. I would love to hear from you.
For more information about who I am, what I do, and, most important, what my dog looks like, please visit my website.
After you have read a few posts, if you find that you're enjoying Shelf Life, please recommend it to your word-oriented friends.
Many thanks to my Dad for helping me get the math mathing!