How Many Columns Should I Use?

If you look at very many product manuals, you will quickly discover that there is no agreement about how many columns to use. Even if you narrow it down to manuals that use a standard 8 1⁄2 X 11 page size, you will see single-column, two-column, and even three-column layouts. Which is best? How do you decide?

The best column layout for your manual depends on several interrelated factors, including these:

• What size font you use
• Whether your columns are right-justified
• What kind and size of illustrations you use

The smaller your font, the shorter the line length you need to ensure that your readers will be able to track properly from the end of one line to the beginning of the next. A good rule of thumb is that your line length should be about 50 characters long. If you look at the average book, you will see much longer line lengths, but remember—people don’t read manuals the way they read novels. Product users tend to look back and forth between the manual and the product. A shorter line length makes it easy for them to find their place.

If you choose to have fully-justified type in your manual, so that the left side and the right side of a block of type form straight lines, you’ll need to avoid very narrow columns, as you would find in a three-column layout. Right-justification requires adjusting either the space between words or the space between letters (or both). A narrow column doesn’t give much wiggle room for adjustment, and you will often end up with awkward spaces. Take a look at a newspaper—which traditionally uses very narrow columns—and you won’t have to look far to find an example. Either you will see a large gap between words or a single word will be s t r e t c h e d to fit.

Illustrations should either fit within the column width or run the full width of the page. If your illustrations are generally large, a single-column layout may be best for you. On the other hand, smaller (but still clear) illustrations might tuck nicely into a two- or even three-column layout.

One alternative is to have two columns of unequal width. Often referred to as a 2/5 layout, this arrangement features a narrow column (around 2” wide) on one side of the page and a wider column (around 5” wide) on the other side. The narrow column can be used for illustrations, notes, or special emphasis. If you use this layout, the narrow column usually appears either on the inside (toward the bound edge) of each page or on the outside, so that facing pages are mirror images of each other.