Optical Sizes

[frankrolf]

@ReymundS and @late2game will handle the extension of Source Serif into optical sizes Display and Caption. This issue is for tracking the work, and for answering any questions.

[RuixiZhang42]

Since Source Serif Pro Math #13 is also on the roadmap, it would be nice to also include a “Tiny” optical size for the second-order sub/superscripts as well (Caption could be used for first-order sub/superscripts).

I’ll add some links to the Source Serif Pro Math thread.

[frankrolf]

Thank you for the kickoff meeting today, Reymund and Thomas!
Here are the scale values I used to prepare the first step toward Caption- and Display masters:
https://gist.github.com/frankrolf/44ebc3c8157bef1591e0174d95fe09a6

[frankrolf]

This is the normalizeAll shell script I use: https://github.com/adobe-type-tools/shell-scripts.
UFOnormalizer needs to be installed, which can just be done using pip or pip3 (see instructions here: https://github.com/unified-font-object/ufoNormalizer )

[ReymundS]

• Frank recommends an adaptation/modulation of the (head)serifs in both »Caption« and »Display«.
• »Caption«: Inktraps in the bold version to be proofed.
• Frank basically agrees with the proposals for f, g, t, ß as well as the cyrillic “d”, “l” – but also with the basic parameters.

Source Compare.pdf

[frankrolf]

You brought up an interesting point with the relationship of Д vs Л. I discussed this screenshot with Maria Doreuli, see below what she has to say:

I find the right one better related to the Л and I think it makes sense. Although to my eye the left side of the right version of the Д is a little too static and the bottom left horizontal segment a little too short.
The new form will help to avoid a large space on the left of the glyph and also perform better in Bolder weights
The left stroke should still be rather diagonal than vertical

So while the modification is welcome, it needs to be less heavy-handed – please make sure the left stroke still curls, has some kind of diagonality, and please don’t shorten the platform of the “teeth”.

---

Concerning the horizontal top of those teeth – I was thinking about this a lot, and I actually think it’s counter-productive to make them look exactly like the serifs. The weight needs to be present, and filing on the top removes quite a bit of it. What I would suggest instead is making other occurences of the vertical teeth horizontal, or at least thicker on top. Here are some examples from other typefaces:

[late2game]

Glad Maria approved the quick and dirty proposal.

I tried to follow her instruction and made the left stroke a bit more diagonal and got back to the original teeth. I also tried to streamline the dot droplets so that they evolve a bit better throughout the weights.
Maybe you should show this to Maria again to be sure that we are on the safe side.
The SC are still to be done, but I'd like to have your and/or Maria's GO before I continue.

Below are 2 screenshots that show the result for all 3 roman weights for UC and LC as well as a PDF for closer inspection.

Source Serif CYR De + El.pdf

[late2game]

We already had a quick chat on the ending of the LC terminals and I'd like to share this here.
We agreed that it's a good idea to have the terminals ending straight for Display, but we didn't agreed if all should end straight or only the top terminals of m, n, p, r.

Source Serif LAT terminals.pdf

[frankrolf]

Since Source Serif follows Fournier in some (not all) decisions, I think it makes sense to consult the source material in this case. Here is an example:

As we can see here, most top terminals are straight, some even slightly angled forward.
Angled top terminals are a good idea in text sizes to avoid clumping, but since you are working on the display style, I agree it sounds like a good idea to straighten them.
One thing I’m noticing though – in the p it looks like the incision from stem to bowl became shallower – is that an optical illusion, or a deliberate change? I think it needs to be a little deeper (compare w/ n).

[late2game]

Ok, so we make all terminals straight. The difference in incision is deliberate since it appears in the text, but it seems that it gets more obvious with straight terminals.
See screenshot below left = text, right = display.

[frankrolf]

Concerning ДЛ - here are comments from Maria:

Source.Serif.CYR.De.+.El.pdf

[late2game]

All her comments make sense and will be implemented these coming days. I'm surprised we even got a "nice" from her, that's not very common with native speakers.

[ReymundS]

As a visual reference for the first commit there is the following PDF showing UC and LC (all upright masters) in both »Caption« as well as »Display«.

Source Serif C-D.pdf

[frankrolf]

Dear @ReymundS and @late2game, thanks very much for your work!
It all looks very promising, and I think we are going in the right direction on either end of the spectrum.
One of the largest changes I propose is that the Black display master could maybe even get a little more contrast.

I have marked up a few things in the PDF proof, see here:
Source Serif C-D_marked up.pdf

[late2game]

Dear @frankrolf, thanks for the fast and productive feedback!
The increased contrast in Black is quite beneficial.
Before I'm going to make another commit to Display I'd like to show you a PDF that has all the latest changes. Please, have closer look on the last 3 pages where I've some doubts.

You can find the latest Display PDF here:
Source Serif Display update.pdf