choose the right "Unit per Em"

Glyphs
1

In my type design class, I was taught that the glyph box (units per Em) is equal to 1000.
I’m working on a typeface with significant ascenders and descenders, and I have three options:

  • Enlarge the box (for example, in the Monotype Italic, I saw that the unit per Em is 2048)
  • Fit the entire glyph into the 1000 box (but the letters would end up too small)
  • Continue with the 1000 box and let the ascenders and descenders extend beyond the box.

What do you recommend?

Unfortunately, I started my work with 800 ascenders and 392 descenders (over the standard 1,000), so resizing the font within the 800+200 box would be a significant adjustment to the letterform.

Thank you in advance for your attention, and please keep in mind the importance of compatibility with software like Microsoft Office and my desire to export the font in both .otf and .ttf formats.

2

A higher UPM does not afford more space, it’s just a higher revolution. So, you would increase the UPM when working in a font with fine details benefiting from a finer grid onto which to place your points. However, the available space would be the same as with a lower UPM.

3

Have a look at Vertical metrics | Glyphs