In example above, the x-heights have been matched in order to illustrate the relative difference in ascender heights.Ascenders usually exceed the cap-height by at least a little, especiually in text designs.
The other oddity in type design is that to very large extent the forms we are designing are already significantly established.It is also useful to recognize that these characteristics not only help to create a font’s voice or atmosphere, but also determine what the font will or will not be useful for, and they sometimes help detemine the technological contexts for which a font is suitable.It may seem intimidating or excessively abstract to think about the design of a font in this way.Our task as type designers is not so much to create an utterly new form but rather to create a new version of an existing form. Finding the just right amount to change in order to excite but not to alienate a reader is a tricky thing.Often designers get stuck in letter-specific thinking.In the example above, the white line inside the letters indicate the approximate construction suggested by the shape of the letters themselves.
The letters on the left come from Playfair, which has a large x-height relative to its cap-height.
Construction refers to the underlying strokes that form a particular glyph.
The kind of construction you use is arguably one of the most important questions to think about, because the construction implies so much about the remaining choices, particularly if your design is going to feel somewhat familiar to readers.
The letters on the right are from EB Garamond, which has a smaller x-height.
In the sample above, the size of the H has been adjusted so that they match.
However, getting used to these ideas is the key to a faster, more effective, and satisfying type design process.