Crafting the Perfect Vertical Rhythm: Mastering Line Heights in Design
What is the optimal amount of whitespace surrounding a line to enhance readability?
In the era of printing presses, the term “leading” originated from the thin strips of lead metal inserted between lines of type to increase vertical spacing and enhance readability. In traditional typesetting, leading referred to the distance between baselines of consecutive lines, measured in points. Typewriters back then had very limited leading options — typically single spacing, double spacing, and occasionally 1.5 spacing for the fortunate few. Similarly, modern word processing software utilizes a comparable measurement system for line spacing, employing the “point” system inherited from traditional typesetting practices.
In design jargon, the term “line height” is used to refer to the vertical space between lines of text. However, the idea behind it is essentially the same as the old-school concept of leading. Tweaking the line height can make a significant difference in how readable and appealing text appears, especially in lengthy documents or when working with larger font sizes.
When done seamlessly, it goes unnoticed, but if it’s not quite right, it can create significant challenges for readers, hindering their understanding and readability of the text.
If you ask a designer to define line height, they’ll likely give you a consistent answer: “Line height is the vertical distance between two lines of type, measured from the baseline of one line to the baseline of the next.”
However, when it comes to how designers apply line heights to different typography fonts, you’ll find a wide range of approaches. Each designer may have their own preferences, using various measures like em, rem, points, pixels, or percentages, depending on the context and their personal style.
After research, it’s clear there is no universal standard for line height values. Different platforms like Medium (1.6), Google (1.58), and Reddit (1.75) have adopted their own guidelines based on specific considerations. Line height is subjective, influenced by factors like font choice, content length, is it print/web based and desired aesthetics.
So, what is the golden rule for line height?
Here are some personal insights, drawn from my experience in product/UX design, that have been instrumental in my understanding of typography and effective utilization of line heights:
The optimal line height typically falls within the range of 120–180%, though it’s not a one-size-fits-all solution for every font or context. Through personal experience, I’ve developed a set of steadfast rules that consistently yield excellent readability.
Three best practices I religiously follow are:
- For single-line text, opt for a 120% line height.
2. When composing paragraphs, adjust line spacing between 130% and 180%, tailored to font size and type.
3. When text accompanies an icon, align the line height closely with the icon size. For instance, if a button features a 40px icon alongside text with a font size of 24px, I aim to match the line height of the 24px font with the 40px icon. This is the only instance where I fix the font size using pixel values.
Moreover, individuals with dyslexia often benefit from increased line spacing, as it enhances readability. Ideally, this spacing should be proportionate to inter-word spacing, with a preferred ratio of 1.5 or 150%. For further insights into how font size and line heights impact individuals with dyslexia, I recommend Dyslexia friendly style guide.
In conclusion, mastering typography and line heights is a journey that goes beyond rigid rules, requiring a deep understanding of design principles and user needs. While aesthetics are important, prioritizing readability is paramount. Typography should not only be visually pleasing but also accessible to every user, regardless of the device they’re using.
While this blog has provided insights into typography for web and print formats, there’s still much to explore, particularly in responsive design for smaller screens like mobile phones. Stay tuned for future posts where I delve into these topics further. And if you’re a seasoned designer with additional insights, I welcome your feedback and corrections as I continue to learn and grow in this field.
If you’ve made it this far, thank you for joining me on the journey through my inaugural blog post. Stay tuned for more insightful content on UX and product design in the future. I’m Sakila, and I’m excited to share my thoughts and experiences to not only clarify my own mind but also to support and inspire fellow product designers along the way. Let’s embark on this learning adventure together!
Also, Follow me on LinkedIn.
