Baseline misalingment in font family

Glyphs
1

So, I have a font family that overlaps onto each other. In previous renders I have had no issue with the family lining up perfectly. But now, with a recent render, one layer does not exactly line up along the baseline with the others, but only in specific circumstances. (Image below.)

As you can see, this top black layer’s baseline has jumped to meet the top of the letters instead of staying on the shared baseline of the magenta and white glyphs. This does not happen in InDesign, or type on a path in Illustrator, but only in a type box in illustrator. (and, again, I was not having this issue with previous renders.) Any insights?

2

Depending on the text frame options (if you have set it to “ascent”), having different ascender values in the fonts would lead to the offset.

3

So, in your case, I’d either make sure that all vertical metrics settings are the same throughout all fonts. Or, you can override the automatic calculation with the corresponding Custom Parameters: take a look at Vertical Metrics in the glyphsapp.com blog.

4

mekkablue

It looks like all my metrics are identical across the entire family.
I will admit that maybe this is an app issue, not a font issue. But I still do not understan why it would bump it up. I figured that there must be some information that the font is feeding the app to do that.

Any other suggestions?

5

This might be about the bounding box of the font/letters. Try to make at least one glyph in the black font the same height as the other glyphs.

6

Well, my bounding boxes are all exact replicas (it’s just the glyph & box duplicated on top of itself)

example A

This example is interesting in that there is no image in the top (black) glyph to cause the letter to jump and align with the cap-height instead of the baseline, but it still jumps. It seems to me to be something coded into the glyph

7

Dan, can you send me the Glyphs files, I’ll have a look at it. (mekka at myusernameinthisforum dot com)

8

I have just noticed that in my Masters I have nothing entered for vertical or horizontal stems. Would this have any issue here?

9
I think Georg was talking about the fonts’ bounding boxes, i.e. the extremum points in the respective fonts themselves. From what I see here, it’s likely that the ‘black’ font’s top extremum is lower than the one of the other fonts.
10
No. Those values are there only for hinting (and the Transformations filter’s Cursify, and Tim’s Remix Tools).
11

mekkablue

I have sent over the working Glyphs files. Let me know what you think. Thanks!

12

As Georg suspected, it’s a font bounding box issue. Some of the vertical metrics are calculated based on the bounding box. You can set them manually, though. The blogpost about vertical metrics explains how. To cut a long story short, you can copy the following text and paste it into each font’s Custom Parameters:

(
{
openTypeHheaAscender = 800;
},
{
openTypeHheaDescender = -200;
},
{
openTypeHheaLineGap = 250;
},
{
openTypeOS2Ascender = 800;
},
{
openTypeOS2Descender = 200;
},
{
openTypeOS2LineGap = 250;
},
{
openTypeOS2WinAscent = 1000;
},
{
openTypeOS2WinDescent = 250;
}
)

13

Alright, after much experimenting, I stumbled across ‘Raise or lower the first baseline in a text area’ on this website.

By default, Illustrator measures the height of your lowercase d and uses it as baseline offset in area text. You can change that in Type > Area Type Options, and there you can have AI calculate the offset (‘First Baseline’) differently:

(Source)

I recommend to always set it to ‘Em Box Height’ or ‘Leading’.