Hi,
I’m working on an experimental variable typeface with multiple shapes in each character. I recently did some tests and found the shapes appear different in illustrator after exporting. I’ve been working with an adjusted grid–with the units per em set to 1800, grid spacing at 2, with subdivisions at 20.
Are there any steps I could take during exporting that could help?
The image below with the overlapping paths are the shapes in illustrator, the other is how they appear in glyphs.
Have you checked other environments (FontGoggles, browsers)?
Variable fonts do not support fractional coordinates (in the current form). So a 2/20 grid will cause rounding. That might cause some misalignment.
It’s looking similarly mis-aligned in FontGoggles. I’m curious what the limits are for variable fonts in making the grid bigger. Are there general sizes I should stay within? I saw in an older post that when units per em go above 2000 more problems are likely to occur, so I tried to keep it below that number.
As Georg pointed out, fractional coordinates are not supported in variable fonts, so your result will be the same in FontGoggles. Try upping the UPM instead of changing the subdivision or grid spacing.
Also–I think you are probably right about the fractional coordinates. Would a solution be to just scale the character up so it’s much bigger? I wanted to avoid that, but it might be a possible solution.
As I pointed out, just up the UPM. That essentially gives you a higher resolution (like you are trying to achieve with your subdivision).
In Font Info > Font, click on the arrow icon next to the UPM field (do NOT edit the UPM value directly). This will invoke the Scale to UPM dialogue. Enter a new UPM (for example, 4000, that should be more than enough). Where did you read that >2000 UPM is problematic? I’ve worked on quite a few projects that choose 2048 (legacy reasons), and I’ve not heard any complaints.
You won’t get perfect results, I’m afraid, but they should be good enough not to be noticed.
I don’t remember where I read about staying below 2000, it was an old post. But the glyphs handbook mentions that indesign and illustrator could experience problems above 3000, in the UPM section. It doesn’t state that you shouldn’t go above this number, but just to be cautious of possible issues.
The UPM problems where in Illustrator above 4000 with cubic outlines when converting to outlines a long time ago. So it might be fixed by now.
And Variable fonts use TrueType outlines. It should not have those problems. But TrueType outlines have a maximum coordinate space. And the max upm (per spec) is 16384.
You can try this, but you need to thoroughly test the font if you go above 4000.
