The technique of determining ascenders & descenders has been discussed recently in font critiques. I think it deserves it's own discussion.
@Hrant H. Papazian mentioned his technique here.
Here's how I determine my ascender/descender levels.
I work from the heaviest weight and design my f. I decide if I want to keep the f crossbar aligned with the x-height. I need to decide where it's more important to keep the ascender low or to keep the top of the f from looking crushed. Then I use the f to determine the height of the lowercase L and i. The ascender height doesn't have to align perfectly with the f , it just has to flow nicely. You can come up with all the theories you want but that fat f has plans of its own.
Next, I work out the g and y. The relationship between these letters is crucial so I design them simultaneously. I go back and forth, making adjustments. When I'm testing, I'm seeing how it looks in words with ascenders. Making sure it feels balanced. Or unbalanced if that's what I'm going for. Then I based the other descenders on what looks best with the g and y. I'm not too concerned about using up valuable descender space because the descenders usually aren't the lowest glyphs. The comma accent and lower circumflex almost always lower than the ascender unless I'm deliberately crushing them. In the lightest weight, there's less pressure on the top of the f and the x-height is usually different. I re-evaluate the ascender and descenders try to maintain the balance established in the heavy weights.
I'd like to hear how other people determine their ascender/descenders.
@Hrant H. Papazian mentioned his technique here.
Here's how I determine my ascender/descender levels.
I work from the heaviest weight and design my f. I decide if I want to keep the f crossbar aligned with the x-height. I need to decide where it's more important to keep the ascender low or to keep the top of the f from looking crushed. Then I use the f to determine the height of the lowercase L and i. The ascender height doesn't have to align perfectly with the f , it just has to flow nicely. You can come up with all the theories you want but that fat f has plans of its own.
Next, I work out the g and y. The relationship between these letters is crucial so I design them simultaneously. I go back and forth, making adjustments. When I'm testing, I'm seeing how it looks in words with ascenders. Making sure it feels balanced. Or unbalanced if that's what I'm going for. Then I based the other descenders on what looks best with the g and y. I'm not too concerned about using up valuable descender space because the descenders usually aren't the lowest glyphs. The comma accent and lower circumflex almost always lower than the ascender unless I'm deliberately crushing them. In the lightest weight, there's less pressure on the top of the f and the x-height is usually different. I re-evaluate the ascender and descenders try to maintain the balance established in the heavy weights.
I'd like to hear how other people determine their ascender/descenders.