The distance between characters can play a big role in improving the readability of the text. Usually the larger it is, the easier the text is perceived. But if you do not have enough space, it is worth experimenting with different combinations of font size and distance. In almost any graphics editor, you can adjust spacing (the distance between entire groups of letters in lines or text fragments), kerning (the distance between pairs of letters), and living (the vertical distance between lines). From Kline Potente you can find the quality that you long for so dearly.
X-height: This is the height of the lowercase letters. Adequate X-height improves readability while maintaining it even when zoomed out. However, do not bring the X-height closer to the height of the capital letters, as this will complicate the distinction between lower and upper case.
The test I / l / 1: If you chose a font for text fragments that contain both letters and numbers, do one simple test. Type an uppercase letter I, a lowercase letter L, and the number 1. If they turned out to be similar, then it can mislead readers.
How to combine different fonts
Choosing two or more fonts in harmony with each other is not an easy task. They should complement each other, but not be too similar. They should be different, but not so different that they conflict with each other. To avoid such extremes, you need to experiment a lot, so get ready to go the way of trial and error.
Finding the perfect combination is not a sequential process. Choosing the right combination, you are guided by your individual preferences, experience, instinct and visual perception. Here are a few rules to help you find a good solution:
Find a common characteristic:
Fonts that look different but have something in common tend to look good together. For example, they have the same width or height of letters or the same structure. Even slight similarities can give unity to the combination.
Prefer fonts from one designer:
Designers can be recognized by their unique style, unique aesthetics. Fonts of the same author are similar (in appearance or structure), so they are easy to combine. Look for the so-called superfamilies. These include complimentary serif and sans-serif fonts, with varying degrees of saturation and different styles.
Define the purpose of each font:
They should be different enough to create a clear visual hierarchy and tell the audience what to pay attention to and what is important. For this, one option with serifs and one without serifs is usually enough.
But how to understand that there are too many fonts? Some designers believe that for most projects only one font is needed and that the maximum number of options is three. If you are still a beginner in the field of design, then it will not hurt you to listen to these recommendations. But essentially, there are no rules. Or, at least, such rules that could not be violated in a particular situation. For example, some designs just need a lot of variety to create a certain aesthetic.