Hello All,
I am working on a font that is easy to read and want to try and force a reasonable space between the x heights
I have a fairly large x height of 1130 funits and was wondering about a typo ascender of 1830. Is that a functional typo ascender or too big
I notice most are smaller.
Anne
I don’t know the answer to your question, but maybe other people can give advice if you provide some screenshots.
The tutorial about Vertical Line Spacing might help you with setting correct values for your font.
Thank you I have read the vertical line spacing tips you suggested.
I thought I understood the basic consepts of it but when I added up the typo ascender and descenders and with or without the line gap I could not get arial or times or Calibri to add up to 2048.
Also the recommendation of not more than 3/4 of upem (2048) would suggest that a max cap height for a font is 1536. I am not sure I have understood this correctly
They don’t have to be 2048.
Yes, that is what we recommend. This is not a requirement, so feel free to do whatever you think is best for your fonts.
From the linked article
TypoAscender and TypoDescender should at least sum to “units per em” (upem). Take the maximum and minimum vertical outline positions from all glyphs that cover the primary languages your font supports. Usually an extended Latin character set, for example Unicode blocks Basic Latin along with Latin-1 Supplement, will do. Then proportionally increase the values so that they total upem.
Set the TypoLineGap value between 7% and 25% of upem, so that the total of all three Typographic values makes a good default line spacing.
Hello,
OK I understand so far. The next step is how does Font Creator fit in with this. Still working on making sure I have a generous line gap or space between the x heights is what I want to achieve. my current x height is 1130. When I press calculate MAX on the metric properties tab it gives me a line gap of 16 - my current asc is 2293 and my decender is 585. If I press calculate MIN asc = 2082, desc = 575 and line gap is 237. How are the line gaps of 16 and 237 achieved or worked out. 23% of 2293 would be more like 520 line gap. 
I have screen shot of the various fonts with their different line gaps calibri has a nice amount of space round it.
TypoAscender and TypoDescender are calculated as described in the tutorial and should give a good indication what is best related to the outlines in the font.
Line gap is a best guess, so feel free to change it to your liking.
I calculate line gap to make line-spacing of 10pt text and even multiple: 12, 13, 15 pt etc. This makes calculating the number of lines that will fit on a page easier, and harmonises between different fonts (most of mine use 1.2 or 12pt line-spacing for 10pt text).
It is very much a personal choice of what you think looks right. Look at a full page of text to see if it looks cramped. For body text, tighter line-spacing uses fewer pages, and therefore saves money, but if you overdo it the text will be uncomfortable to read.
Hello
Thank you both for helpful comments,
I have played around drawing fonts and letters for years and years, however I am unaware of a lot of the professional names and terms in serious font building. Can I check I have understood this OK
You usually have 12 point line spacing or 1.2: how does that translate into the numbers on the line gap. would it be a line gap of 12 or 2 or a 12% of the total minimum ascender and decender added together. eg : my total ascender and decender is 2657 and 12% of that would be a line gap of 318.
or none of these!
Anne
I notice Bhikkhu, you live in seven sisters. That is easy for me to get to, so I am thinking if you do any small group or one to one training classes - I would love to have a day or two on how to use open type tables and the functions behind just the drawing of fonts. I have done database programming in SQL but have only managed to get the concept of the scripts for open type and not the precise words and formats.
Anne
I live in Seven Kings, not Seven Sisters, which is the other side of London. The only training sessions that I do are for mindfulness meditation.
Oh yes i just looked on the map as i havent heard of seven kings.
Not really close. Just a thought
Do you have any comments on the text above that one on what
The conversion to line gap figures equal.
Anne
2657 + 5 = 2048 × 1.3 so a line gap of 5 will give you 13pt line-spacing for 10pt text.