Size is an incredible tool that magically announces to people what is most important and what is least important. Whether you’re creating a résumé, a sales report, or a flier (or anything else), you should think about how contrasting the size of text and images will guide people to what matters most. Remember from the rule, Write for How People Read that most people don’t read much anymore—they skim and scan. Contrasting information using different sizes does three things: it grabs attention; it layers and chunks information; and it creates a hierarchy of importance.
Use Size to Grab Attention
It may go without saying that things that are bigger grab more attention. It’s human instinct: even if we had no idea how dangerous any particular animal is, we know we should pay more attention initally to a shark than a guppy. When you make a title, heading, or image bigger than something else on the page, people will look at it first. Choose what’s most important and make it the biggest.
Use Size to Layer and Chunk
In addition to grabbing attention, making things different sizes draws attention to different types of information. When creating a layout that includes different types of information, consider making each information type a different size. For example, you might want to have a page that includes a main title, a summary of the content, some body text (with headings), and a block quote. If you use distinct (and obviously different) sizes, readers will be able to easily separate the information because you have layered and chunked it for them. Plus, it will just look more visually interesting, which you can never go wrong with.
Use Size to Creat a “Bite, Snack, Meal” Approach
Size can also be used to give people a sense of depth, progressively giving them the information they need. It’s sort of like walking into a networking event where you weren’t planning to eat at all (you have a dinner reservation later with your spouse). Once there, though, you discover some tasty-looking hors d’oeuvres and you say to yourself, “okay, maybe just one little bite.” Once you’ve tasted that delectible meatball-on-a-stick, though, you find yourself “snacking” on a few more of the options—artisan crackers, coconut shrimp, and the to-die-for roasted red pepper hummus. Before long, you’ve gone through two full plates—plus a slice of cheesecake and a cookie—and you’re calling it a “meal” (only to later disappoint your hungary spouse).
Size in information design does this same thing—the biggest, most obvious thing gives people a sample (or a “bite”) first. If they like what they see, they begin to “snack” on other elements—they read the headings and look at a few pictures. If they are still hooked, they’ll feast (“meal”) on the rest of the content—the body text and details. Help you reader out by progressing them towards what they need (or don’t need). If you give them the meal all at once, but they didn’t come to eat, they may just walk away.
Use Nesting Effectively with Your Headings
“Nesting” means layering content into categories and subcategories, or using headings and subheadings. While you want to nest information to layer, chunk, and use the bite-snack-meal approaches mentioned above, note that it’s usually not effective to create more than four layers of nested headings. When you “nest” information, it can be confusing for readers to follow a trail of too many different sizes of text. Stick to no more than five sizes of text on a page: a title, a major heading, a subheading, (possibly) one sub-subheading, and the body text. If you can limit to three or four, that’s even better.