Is there an optimal setting for exporting a font file for sending the files to an external font hinting provider?
Is there something that should be activated/deactivated in the export options, should it be TTFs or OTFs or it does not matter. The TTF hinting will be done in Fontlab by the service provider.
Also I find that the filter AddExtremes does not always add extremes, especially in thin weights and the such.
Is there a way to force addExtremes?
Thanks!
If you what to do TrueType hinting, you should export as TrueType. Otherwise you loose components.
The AddExtremes filter only adds extremes if it doesn’t deform the outline to much.
Some things you should keep in mind (unrelated to export settings). Components should not be rotated, scaled or vertically shifted (exception: diacritical marks may be vertically shifted). Glyphs cannot contain both outlines and components. You don’t have to flatten overlaps, though you should be aware there are some minor rendering issues.
Be advised: The export-to-vfb scripts are not reliable. It is better to export ttf, make a copy of the temp folder that Glyphs generates, add hinting to the ttf, and generate the makeotf-project again.
Before you send it out consider just doing it yourself. If you only need y-axis hints for Cleartype and Directwrite it’s very easy to hint with Glyphs 2.3. I hinted the 170 base glyphs in a sans-serif Latin typeface in about an hour and glyphs automatically applies hints from the one hinted master to all 84 instances. This will also allow you to change the design and quickly update your hinting without using other software.
Examples of hinted Latin, Devanagari, and Kannada can be found in the Rhodium and Padyakke repositories of my Github: https://github.com/DunwichType?tab=repositories
Hmm. Glyphs is not ready for quality TrueType hinting yet, as your files clearly illustrate:
Some of these errors can probably be attributed to bad hinting, but many of the smaller details are impossible to control with the current set of tools.
There are things that work better with Glyphs hinting and some work better with other solutions. Make sure that the stems are not set to be rounded. That will result in fractional stem width for grayscale and DirectWrite rendering. This will drastically reduce the distortions and thous the need to fix things. The stems are only rounded on Windows XP as it uses the old GDI-Cleartype. So it does look worse there.
Images above show a little bit of both DW and GDI. Problems everywhere.
Make sure that the stems are not set to be rounded. That will result in
fractional stem width for grayscale and DirectWrite rendering.
@GeorgSeifert: This is not documented. Wouldn’t all instructions referencing a control value be rounded to a full pixel anyway?
I’m proofreading the manual as we speak.
Yes and not. Stems are aligned to a CVT value but the CTV values are not necessarily rounded to a full pixel.
First scale and round everything to the UPM that the hinter wants, then export TTF.
Fonts exported from Glyphs with grid set to zero (not rounded) might open distorted in FontLab, with positions of outlines being up to 10 units wrong, which the hinter might not notice :-).
Thanks all!
James, I have tried hinting in fontlab, VTT (with a little help from Mick Duggan) and Fontlab. I’m more and more understanding the ins and outs of it.
For this particular project, though, I need to make sure the hinting is as good as possible, hence the external provider. I’m not confident in my abilities just yet.
Thanks for the tips. I exported otfs with 0 grid spacing - sure enough things got distorted in FL.
Grid spacing 1 and ttf, looks better (thanks Lucas!), but didn’t export overshoot zones, is there a reason why?
TrueType don’t have zones.
Aha, that’s why. 
