Typography is more than just choosing a pretty font; it’s the art and technique of arranging type to make written language legible, readable, and visually appealing. In design, it plays a key role in shaping user experience, impacting everything from the emotions evoked by a brand to the usability of a mobile app. Mastering typography enables designers to communicate more effectively, guiding users through content in a seamless and accessible way. In this blog, we’ll dive deep into the essential aspects of typography, including the difference between typeface and font, web typography units, the anatomy of type, and best practices for ensuring accessibility.
Typeface vs. Font: Understanding the Difference
The terms “typeface” and “font” are often used interchangeably, but they have distinct meanings that are crucial to understanding typography.
- Typeface: A typeface is the design of a collection of characters that share a consistent visual appearance. It includes variations such as different weights (light, regular, bold), styles (italic, condensed), and sizes. Times New Roman, Helvetica, and Arial are examples of typefaces.
- Font: A font refers to a specific instance of a typeface. It is the combination of size, weight, and style of a typeface. For example, Helvetica Bold 14pt is a font that belongs to the Helvetica typeface family. In simpler terms, the typeface is the design, and the font is the delivery method.
Example: If Arial is a typeface, then Arial Italic 12pt and Arial Bold 18pt are different fonts within that typeface family.
Web Units for Typography: Pixels, em, and rem
When designing for the web, it’s important to understand the units of measurement that control typography. These units affect how text is displayed across different devices and screen sizes.
- px (Pixels): Pixels are a fixed measurement unit that is straightforward and precise. However, using only pixels can lead to less flexible designs, as the size won’t adjust dynamically based on user preferences or screen sizes. Pixels are commonly used for small elements like icons or specific UI elements.
- em: The em unit is a relative measurement based on the font size of its parent element. If a parent element has a font size of 16px and a child element is set to 2em, the child’s font size will be 32px. Using ems allows your text sizes to be responsive, scaling up or down based on the parent context. Example: Imagine a
<div>with a font size of 16px and an<h1>inside it with a font size set to 1.5em. The resulting font size for the heading will be 24px (1.5 × 16). - rem (Root em): rem units are relative to the root font size, which is typically set by the browser or defined in the CSS of the website. Unlike em, rem is unaffected by its parent element, providing more consistency across different components. If you want uniformity in your typography scaling, rem is generally the best option. Example: If the root font size is 16px and you use 1.25rem for a paragraph, the resulting font size will be 20px (1.25 × 16).
Selecting the Right Typeface for Mobile Interfaces
Designing for mobile interfaces presents unique challenges, especially when it comes to typography. With smaller screen sizes and varying resolutions, choosing the right typeface is critical for readability and usability.
- Sans-serif Typefaces for Clarity: Sans-serif fonts like Roboto, Helvetica, and Arial are the most popular choices for mobile interfaces. These fonts have a clean, minimalist design, making them easier to read on small screens where space is limited. Sans-serif fonts are also more legible at smaller sizes, reducing eye strain for users. Example: Google’s Roboto is used extensively in Android’s design system because of its clean, modern look and versatility across different devices.
- Legibility and Readability: Avoid using decorative fonts or serif fonts in body text on mobile interfaces. While serif fonts like Times New Roman or Georgia are great for print or long-form content, their complex strokes make them harder to read at small sizes. Stick to simple, easy-to-read fonts to maintain clarity.
- Responsive Scaling: Using relative units like rem and media queries ensures that your type scales smoothly across different screen sizes. You may want to adjust the font size on larger mobile devices or tablets to ensure consistent readability. Example: Start with a base font size of 16px for body text on mobile devices, then scale heading sizes based on a modular scale (e.g., 1.25 or 1.33) for a cohesive hierarchy.
Scaling Fonts in Your Design System
A well-structured design system helps maintain consistency across different platforms. Here’s how to effectively scale fonts in your design system:
- Define a Base Size: Start by setting a base font size, usually 16px for body text. This will serve as the foundation for scaling your typography.
- Use a Modular Scale: Modular scales create proportional and harmonious relationships between different text sizes. A common ratio is 1.25, meaning that each larger size is 1.25 times the size of the previous one. This creates a visually pleasing hierarchy for headings, subheadings, and body text. Example: If your body text is 16px, using a 1.25 ratio would make your h1 size 20px (16 × 1.25), h2 size 25px (20 × 1.25), and so on.
- Fluid Typography: Implement fluid typography using CSS functions like
clamp(), which allows font sizes to scale dynamically between a minimum and maximum size depending on the viewport width. This approach ensures text remains legible across a wide range of screen sizes without manually adjusting for each breakpoint.
Major Typeface Classes
Understanding the different typeface classes can help you make informed decisions in your design. Each class has its own strengths and weaknesses, making them suitable for different contexts.
- Serif: Serif fonts have small strokes at the end of each character. These are traditionally used in print and long-form content. Serif fonts like Times New Roman, Georgia, and Merriweather create a sense of formality and elegance, but they can be harder to read on small screens.
- Sans-serif: Sans-serif fonts, which lack the decorative strokes of serif fonts, are clean and modern. Popular sans-serif typefaces include Arial, Helvetica, Roboto, and Open Sans. They are ideal for digital interfaces because they maintain legibility at smaller sizes and on low-resolution displays.
- Slab Serif: Slab serif fonts feature thicker, block-like serifs, which give them a bold and attention-grabbing appearance. Fonts like Rockwell and Courier are often used for headlines or branding but may not be suitable for body text in digital interfaces due to their heavy appearance.
- Script: Script fonts mimic handwriting or cursive styles, like Brush Script or Dancing Script. These are decorative and should be used sparingly, typically for logos, invitations, or special headlines.
- Display: Display fonts are designed for large sizes, such as in headlines or titles. They are often decorative and not suitable for body text. Examples include Impact and Bebas Neue.
Type Anatomy: Key Terminology
Understanding the anatomy of type can help you appreciate the nuances of different typefaces. Here are some important terms:
- Ascender: The part of a lowercase letter that extends above the x-height (e.g., the vertical line in the letter h).
- Descender: The part of a letter that extends below the baseline (e.g., the tail of g or y).
- Baseline: The line upon which most letters sit.
- X-height: The height of lowercase letters like x, which defines the perceived size of the type.
- Cap Height: The height of capital letters.
- Kerning: The space between individual characters. Good kerning ensures letters aren’t too close or too far apart.
- Leading: The vertical spacing between lines of text, measured from baseline to baseline.
WCAG Guidelines for Typography: Accessibility Best Practices
Design isn’t just about aesthetics—it’s also about accessibility. Following the Web Content Accessibility Guidelines (WCAG) ensures that your text is readable for all users, including those with visual impairments.
- Font Size: WCAG recommends a base font size of at least 16px to ensure text is readable for users with visual impairments. Avoid going smaller than this for body text.
- Line Height: A line height of at least 1.5 is recommended for body text to improve readability. This prevents text from feeling cramped and difficult to read, especially for users with cognitive disabilities.
- Contrast Ratio: Ensure that your text has a contrast ratio of at least 4.5:1 against its background. This is critical for readability, especially for users with low vision or color blindness. Example: Use a contrast checker tool to verify that your text is readable against its background.
- Sentence Length: Limit the length of lines to 50–75 characters for optimal readability. Longer lines can make it difficult for users to track where they are on the page, especially on large screens or desktop monitors.
Conclusion
Typography is a key element in design that goes far beyond simply picking fonts. Download a brief quick guide to typography here
Sources:
- WCAG 2.1 Guidelines, Understanding WCAG 2.1, W3C: Web Content Accessibility Guidelines (WCAG) 2.1
- Ethan Marcotte, Responsive Web Design, A Book Apart, 2011
- John D. Berry, Type & Typography, Thames & Hudson, 2006
