I am not a Multiple Master Master

I am working on a big project file with seven different masters on two axis.

The structure is as follows:

Ultralight | Extended ——— ——— ——— ——— Ultralight | Narrow

Regular | Extended    ——— ——— ——— ——— Regular | Narrow

                      ——— ——— ——— ——— Bold | Narrow

Heavy | Extended   ——— Heavy | Regular

The reason for this setup is so that I can have a heavy weight with enough heft to it while also doing an instance that is as condensed and as bold as possible.

My issue is this, when I am using the file as a variable font, or even just when I am exporting all my placed instances I am getting a rugged transition once I go over the breaking point of the Regular.

There is a sudden spike of weight gained when I cross from (o) to (x)

Ultralight | Extended ——— ——— ——— ——— Ultralight | Narrow
Regular | Extended    ——— ——— ——— ——— Regular | Narrow
                      ——— ——— ——— ——— Bold | Narrow

Heavy | Extended   ——— Heavy | Regular

My first thought was, that my math for the setup is in somw way wrong. However I triplechecked the setup and I think it is correct. And even when I change the numbers, the sudden spike stays there.

Even when I delete Bold | Narrow I have those issues.

The only time I am not getting any issues is if I delete Bold | Narrow and change the width property of Heavy | Regular to Narrow.

At this point I am out of ideas, so any help would be greatly appreciated!

Hi, I’m afraid I don’t quite get the picture of your setup. Could you just write your master values here? Like this:
1: UltraLight Extended (30, 150)

7: Heavy Narrow (250, 70)

Or whatever else you use as your weight, width values. Or, if you feel comfortable doing so, you’re welcome to send me the file and I’ll take a look at what’s up with it :slight_smile:

Sure thing. Setup is as follows:

Ultralight Extended (100 682)
Regular Extended    (400,682)
Heavy Extended      (900,682)
Ultralight Condensed(100,100)
Regular Condensed   (400,100)
Bold Condensed      (685,100)
Black Regular       (900,464)

The issue arises when I cross over the weight of 400 while being in between widths. Like for example from:

(400,500) --> (401,500)

Do I read this correctly that you don’t have a Black (or Heavy? What name are you going with? :slightly_smiling_face:) Condensed master? You may be extrapolating at a certain point. I’m still having trouble visualising this exactly and I can only guess in the dark. Can you see what happens when you re-interpolate some of your in-between masters? Make sure to create a backup file first, of course, but then you can select all glyphs (or just one, maybe, if that’s visual aid enough) of a master and rightclick + re-interpolate in the layers panel. See how much changes, that can give you some idea as to whether some of your masters are malpositioned.

Alright so I made a small Visualisation of my Designspace.

I also made a short Screencapture so you can get a better feel for how the font behaves.

Visualisierung.pdf (381.5 KB)

Variable fonts need a rectangular setup. And you can’t hide corners like time top left in your diagram.

Yes, this is what I assumed. So, that means: you need a master at (900, 900), too, so that all the extremes of your design space are defined.

Georg, can you tell me why this is required? Theoretically, it would seem feasible for a setup like the above to suffice.

Yes, putting in the missing master fixed the biggest intepolation problems.

Do I also need a master that ist bold,extended, or is it only important to have the corners of the rectangle covered.

The requirements are a bit difficult do explain here. This article is a bit long but contains what you need to know: https://medium.com/variable-fonts/https-medium-com-tiro-introducing-opentype-variable-fonts-12ba6cd2369

It is only necessary to cover the corners of your design space (the extremes). You can add however many masters you want in this rectangle, but it’s generally a good idea to start designing only with the extremes and only adding intermediate masters when needed.

Thank you very much, Georg! Great resource.

You don’t have a 900 width, so I assume you’re asking about e.g. wght900, wdth682?

You do not need, according to the spec, to put a master there, or any corner that works when the extremes of the two axes that define it, create a corner the works by themselves.

This is often possible if the ranges and wdth and wght are “reasonable”.

It may not be clearly stated in the ot specification because the authors and advisors didn’t seem know it when they were writing the spec.

If I understand both of you correctly, that contradicts what Georg wrote earlier – and seems to be inconsistent with the fact that adding the master “fixed the biggest interpolation problems”. Of course, technically, you can do without it and will still receive valid font files, but the with the desired interpolation. Or am I understanding something wrongly?

Extrapolation to empty corners also depends on the origin, doesn’t it? A good article: https://superpolator.com/designspace.html