Be very careful with your column choices—especially in books. (It’s the main reason blogs and ebooks are so hard to read.) Your focus must be easy, comfortable readability. Generally, the asymmetrical (off-center) layouts with wide margins are good. Of course, you can go crazy and make things totally illegible. Modern style tends to be chaotic, splashy, and overly complex. But your innate taste and discretion should keep these tendencies in check. The problem, of course, is that taste and discretion have become rare. I know you are working hard to learn taste and reduce that trend. Thank you.
The basic concept is to focus on the reader: You are writing to serve your reader. If you are not doing this, you need to have a little talk with yourself about why you are writing in the first place. Books are a very conservative piece of design. The typography needs to be invisible. Your goal is to present the content as irresistible to read and easy to understand. That is the essence of good typography.
This is the width of the basic body copy paragraphs. For many books these paragraphs make up well over 95% of all the copy.
The first assumption is that you have column widths in good, readable range. Basically you are shooting for seven to eleven words per line—increasingly I try to keep my average line length at 9-10 words per line. Once you have a few pages written, then you adjust your font sizes to get the right number of words in an average line of body copy type. You simply count the words in a dozen lines or so and average them (if you need to go that far).
The formula I use for column width is very simple and gives you a good starting point for readability.
Here’s a practical rule of thumb that’s less complex than most:
40% of the body copy point size in inches
or the point size in centimeters
So, 10 point type works well in a column that is four inches or 10 cm wide. 12-point type may need nearly five inches (40% is 4.8”, 12 cm is 4.7″). This assumes a normal x-height of about 50% of the cap height or a third of point size. If the x-height or width of the letters is radically different than the norm you will need to make adjustments. Just adjust the point size until the number of words per is good.
Adjust your margins to leave an appropriate column width
This can be tricky with smaller books. There is a real limit to the smallness of body copy type (about 8 point [and that’s pushing it]). This gives us problems with the smaller book sizes.
The normal body copy size is 10 point type with 12 point leading. I’ve talked about that many times. But it is a fairly rigid norm. This normally requires a four inch column. For a five inch wide book, this only allows for half-inch margins on the sides. As mentioned in last weeks posting, that is very tight. You can probably take the column down to 3.5” with no readability issues, but you dare not go more narrow than that (just be sure to keep the 9 to 10 words per line).
On the other hand, an 8”x 10” book leaves you with four inches of margins. This is not a bad thing. One inch margins on all sides leaves you with an extra two inches for the gutter. This makes excellent room for a sidebar and room to hold graphics up to six inches wide.
For two-column books: it should be easy to see that you need a page that is at least ten inches wide for any visual comfort. Books this wide become difficult to hold and read comfortably—no matter what you do. It is rarely a good solution (though adding a narrow sidebar can be a real benefit in an 8” wide book).
For a 6×9 book: my normal setup is .75” top and outside. I set the bottom at an inch to leave a quarter inch to hold my page numbers. I use the resultant 1.25” inside margin to help keep the copy out of the gutter and make reading more comfortable. There’s no room for a sidebar, but it is a comfortable read.
Lately, I’ve been using a 7″x10″ book with an inch top and outside, an inch and a quarter at the bottom, and two inches on the inside. This gives me good room for a small sidebar, and five inch graphics work fine.