Truetype Font Experts - Default Leading

  Pesala 21:56 30 Jan 2003

I could still find no solution to my earlier question. Anyone know about font editing?

How do I adjust the following parameters to ensure that the default leading of my fonts is exactly 12 points at 10 point font size?

The following values give a default leading of 11.57 points at 10 points

Units / em = 2048

TypoAscender = 1491

TypoDescender = -431

TypoLineGap = 307

WinAscent = 1854

WinDescent = 500

  jazzypop 23:05 30 Jan 2003

click here and scroll down to 'Baseline to Baseline Distances'.

You may also find the following sites useful -

click here

click here=

click here

click here

As previously stated, I am by no means a TT expert.

  Pesala 05:46 31 Jan 2003

The first link you provided is very clear. It didn't seem to work as expected last time I tried it. I will try again later, and post again if it works. Thank you for your help.

sTypoAscender, sTypoDescender and sTypoLineGap

sTypoAscender is used to determine the optimum offset from the top of a text frame to the first baseline. sTypoDescender is used to determine the optimum offset from the last baseline to the bottom of the text frame. The value of (sTypoAscender - sTypoDescender) is recommended to equal one em.

While the OpenType specification allows for CJK (Chinese, Japanese, and Korean) fonts' sTypoDescender and sTypoAscender fields to specify metrics different from the HorizAxis.ideo and HorizAxis.idtp baselines in the 'BASE' table, CJK font developers should be aware that existing applications may not read the 'BASE' table at all but simply use the sTypoDescender and sTypoAscender fields to describe the bottom and top edges of the ideographic em-box. If developers want their fonts to work correctly with such applications, they should ensure that any ideographic em-box values in the 'BASE' table describe the same bottom and top edges as the sTypoDescender and sTypoAscender fields. See the sections "OpenType CJK Font Guidelines" and "Ideographic Em-Box" for more details.

For Western fonts, the Ascender and Descender fields in Type 1 fonts' AFM files are a good source of sTypoAscender and sTypoDescender, respectively. The Minion Pro font family (designed on a 1000-unit em), for example, sets sTypoAscender = 727 and sTypoDescender = -273.

sTypoAscender, sTypoDescender and sTypoLineGap specify the recommended line spacing for single-spaced horizontal text. The baseline-to-baseline value is expressed by:

OS/2.sTypoAscender - OS/2.sTypoDescender + OS/2.sTypoLineGap

sTypoLineGap will usually be set by the font developer such that the value of the above expression is approximately 120% of the em. The application can use this value as the default horizontal line spacing. The Minion Pro font family (designed on a 1000-unit em), for example, sets sTypoLineGap = 200.

  Pesala 15:59 31 Jan 2003

Sanskrit Centurion
Units per em = 1000
TypoAscender = 983
TypeDescender = -206
TypoLineGap = 11 (I increased it from 0)
983 + 206 + 11 = 1200
This gives a default leading of 11.88 (Why?)

Sanskrit Garland

Units / em = 2048
TypoAscender = 1491
TypoDescender = -431
TypoLineGap = 307

Which gives a default leading of 11.57 points

Increasing the TypoLineGap to 536

Makes absolutely no difference (Why not?)

  Pesala 19:02 21 Feb 2003

Anyone have practical experience? I have read the theory, but it doesn't seem to work as expected.

  Pesala 16:30 03 Mar 2003

Still no answer to this one after many weeks.

Try again and see if any new visitors have experience in editing Truetype fonts

This thread is now locked and can not be replied to.

Elsewhere on IDG sites

iPhone X review

How to find a font: Discover the name of a typeface with these apps

The best iPhone for 2017

Comment créer un compte PayPal pour payer en ligne ?