Do we need kerning against the space character?

Post Reply
User avatar
Tim Ahrens
Site Admin
Posts: 172
Joined: 11 Jul 2019

Do we need kerning against the space character?

Post by Tim Ahrens »

So far, Kern On does not do any kerning against the space character. I know that some people do that, however. So, the question is:

Do you want KO to support/generate kerning against the space?

If so, what is the reasoning behind it? What is the (visual/geometrical) reason for it? What are the principles that guide you if you do it manually?

Looking forward to your answers!
User avatar
Jeremy
Posts: 7
Joined: 04 Jan 2021

Re: Do we need kerning against the space character?

Post by Jeremy »

I do look at this, but am aware of combinations such as 'W W' or 'f W'.
Sometimes I have swapped out the space with a space.wide, or space.narrow etc.

I tend to review as a basic in consideration of standards and the whole type. Any kerns are small though.

/H/H/H/space/H/H/H/space/O/O/O/space/O/O/O/H/H/O/O/H/H/period/space/H/H/H/period/space/O/O/O/period/space/H/H/period/space/A/H/period/space/J/H/period/space/M/H/period/space/S/H/period/space/T/H/period/space/U/H/period/space/V/H/period/space/W/H/period/space/X/H/period/space/Y/H/period/space/Z/H/H/H/O/O/H/H/comma/space/H/H/H/comma/space/O/O/O/comma/space/H/H/comma/space/A/H/comma/space/J/H/comma/space/M/H/comma/space/S/H/comma/space/T/H/comma/space/U/H/comma/space/V/H/comma/space/W/H/comma/space/X/H/comma/space/Y/H/comma/space/Z/H/n/n/n/space/n/n/n/space/o/o/o/space/o/o/o/n/n/o/o/n/n/period/space/n/n/n/period/space/o/o/o/period/space/n/n/period/space/a/n/period/space/f/n/period/space/j/n/period/space/s/n/period/space/t/n/period/space/u/n/period/space/v/n/period/space/w/n/period/space/x/n/period/space/y/n/period/space/z/n/n/n/o/o/n/n/comma/space/n/n/n/comma/space/o/o/o/comma/space/n/n/comma/space/a/n/comma/space/f/n/comma/space/j/n/comma/space/s/n/comma/space/t/n/comma/space/u/n/comma/space/v/n/comma/space/w/n/comma/space/x/n/comma/space/y/n/comma/space/z/n

If you add it to Kern On I would possibly have it as an option unless a string of 3 can be considered – i.e. the glyph before the space – '. W' is a larger hole than 'f W' or 'W W'
User avatar
Tim Ahrens
Site Admin
Posts: 172
Joined: 11 Jul 2019

Re: Do we need kerning against the space character?

Post by Tim Ahrens »

Thanks for sharing this!

So, it seems that here, the main reasoning for any kerning against space is triplets? I had this feeling, too, that we don’t need kerning against the space character out of purely pair-based reasons.

Your trick to simply use a contextual space.wide or space.narrow is really good! I had never thought about that. Much easier to implement than triplets, it can easily be controlled in an MM environment, and probably also requires much less data to go into the font.
Eben Sorkin
Posts: 15
Joined: 27 Apr 2021

Re: Do we need kerning against the space character?

Post by Eben Sorkin »

I like to have kerns to space for text faces because it allows me to get a more even grey in a paragraph than I could otherwise get. I aim to make the space itself appear more constant in brightness. In a really large optical size display face I might also want to because all the spacing becomes more sensitive. Space wide and space narrow seem like a great way to get some of this impact without the kerning data overhead. But I really would want to option to automate this with examples if possible.
User avatar
Tim Ahrens
Site Admin
Posts: 172
Joined: 11 Jul 2019

Re: Do we need kerning against the space character?

Post by Tim Ahrens »

Thanks for your contribution, Eben!
Do you use positive or negative kerning against the space, and for which characters?
Eben Sorkin
Posts: 15
Joined: 27 Apr 2021

Re: Do we need kerning against the space character?

Post by Eben Sorkin »

The letters where the word space tends to look brighter/bigger than a default those with big open white spaces. H H no and vs T T yes. The Latin glyphs that I sometimes like to kern with space in caps are : A T V W Y X both sides; Right side L C F P K G; Left side J. The suitability of the gyph to kerning with a word space is very dependant on the design. In lower case the values are smaller because the white space is less but I do also sometimes do right side: c f k t; both sides v w x y. Numbers can also benefit from this treatment. Again depending a lot of the design but these might include: 2 3 4 5 7. Symbols like The UK pound sterling are sometimes quite bright on the right side. The various dashes can feel a bit loose set next to a space. I like to make sure that the nonbreaking space and other spaces that are are part of the word space kerning group numberspace, emspace and enspace for example.
User avatar
Tim Ahrens
Site Admin
Posts: 172
Joined: 11 Jul 2019

Re: Do we need kerning against the space character?

Post by Tim Ahrens »

It seems we need to distinguish different cases of kerning that involves the space character:
  1. Pairs with space that need negative kerning, as the sidebearings of the glyph are always chosen with neigbouring glyphs in mind, which means the “close zone” has to be over-represented. For example, thinking of a typical sans, the sidebearings of the V are not chosen so that the average distance (i.e. at half the cap height) is the same as the H, but looser, as the close zone at the top is not fully compensated by the loose zone at the bottom. Against the space, however, perception works more in terms of average distance or white area, so we need this correction by positive kerning. Examples: [ V] and [F ].
  2. Pairs with space that need positive kerning. Possibly after the f, which is is a unique case in that it is usually spaced specifically to work against LC without ascenders and it is “too tight” from an abstract, i.e. average distance or white area point of view. Example: [f ].
  3. Triplets (with space in the middle) that need to be tightened, as the same principles as normal kerning seem to apply across the space (but maybe weaker?). Examples: [L T] and [. W].
  4. Triplets (with space in the middle) that need to be widened as they would be too tight otherwise. Examples: [W W] and [f W].
User avatar
Tim Ahrens
Site Admin
Posts: 172
Joined: 11 Jul 2019

Re: Do we need kerning against the space character?

Post by Tim Ahrens »

3. Should be the easiest to implement: Just take all kerning pairs, “insert” a space in the middle, possibly apply a taming factor < 1, and export as triplets. Maybe I will try this as an experiment. From a typographic (semantic?) point of view, this may not be as crucial as normal kerning, as the space is meant to separate things from each other, but the increased visual consistency might be beneficial.
bech
Posts: 5
Joined: 27 Apr 2021

Re: Do we need kerning against the space character?

Post by bech »

I just want to add my name to the list, and echo what Eben said.
I spent some time today trying to figure out how this is done in KO before finding this :)
Is the work-around now to hit »Kern On« and then do this manually before exporting?
Thanks!
User avatar
Tim Ahrens
Site Admin
Posts: 172
Joined: 11 Jul 2019

Re: Do we need kerning against the space character?

Post by Tim Ahrens »

Which type of kerning against the space do you want to add to the font (see my list above)? I would advise to add the kerning as independent pairs within Kern On, which allows you to re-run KO if you spot pairs that need a different value.
bech
Posts: 5
Joined: 27 Apr 2021

Re: Do we need kerning against the space character?

Post by bech »

I tried doing that, but it gave me problems so I thought that wasn't the way forward.
There were discrepancies between the main letter (A) and the other in the same group (ÁĂǍÂÄÀĀĄÅǺÃÆ), like missing kerning on one side, and open locks, closed locks.

In the attached example /A/ has the kerning but one of the locks are left open. This results in /Aacute/ on the right not getting the kerning.

Or am I missing something? Thank you!

Edit: I forgot to answer your question. Usually it's 1 and 3, that I think needs to be sorted in some typefaces.
Attachments
Screen Shot 2021-08-01 at 21.22.01.png
Screen Shot 2021-08-01 at 21.22.01.png (153.13 KiB) Viewed 777 times
User avatar
Tim Ahrens
Site Admin
Posts: 172
Joined: 11 Jul 2019

Re: Do we need kerning against the space character?

Post by Tim Ahrens »

Independent pairs are always glyph-glyph pairs. Kern On will not transfer them to other pairs. You would need to set all necessary glyph-glyph pairs as independent pairs (I know that’s not convenient, just a work-around for now).
bech
Posts: 5
Joined: 27 Apr 2021

Re: Do we need kerning against the space character?

Post by bech »

OK gotcha, but is it odd then that Aacute got the -4 kerning on the right from KO?
I will try your workaround for now.
bech
Posts: 5
Joined: 27 Apr 2021

Re: Do we need kerning against the space character?

Post by bech »

Tim, I tried your workaround and made independent pairs for the usual suspects (L, T, F etc.) and /space/ (and the same on the right of /space/ too, of course), but is there a reason why I now get kerning on other letters too? The pairs should be ‘independent’, right? And /space/ is set to ‘No kerning’.
Attached screenshots of E-space before and after applying KO.

BTW, I even got a -114 kerning on /space/ and “straight-sided” letters (H, N etc.) before, but putting an independent pair on space-H solved that. Should an independent pair fix that though? Sorry, I’m a bit confused.
Attachments
Screen Shot 2021-08-02 at 21.39.22.png
Screen Shot 2021-08-02 at 21.39.22.png (182.53 KiB) Viewed 765 times
Screen Shot 2021-08-02 at 21.38.25.png
Screen Shot 2021-08-02 at 21.38.25.png (369.47 KiB) Viewed 765 times
User avatar
Tim Ahrens
Site Admin
Posts: 172
Joined: 11 Jul 2019

Re: Do we need kerning against the space character?

Post by Tim Ahrens »

Thanks for pointing this out.

After seeing this, I realize the handling of independent pairs that include “No kerning” glyphs – when the class kerning is generated – should be refined.

Right now, the reasoning is: Ensure all independent pairs are preserved exactly as they are set, while all pairs that are “not in the system”, i.e. don’t have any of the model/auto/ind segments activated, are ignored and may get any random value. This is ignoring the user’s statement of “No kerning” and that‘s not good.

I’ll fix that, and hopefully add some support for kerning against the space as well.
bech
Posts: 5
Joined: 27 Apr 2021

Re: Do we need kerning against the space character?

Post by bech »

Glad to help. I agree that this part doesn't really make sense right now. But overall, KO seems awesome so far! Your products are the best thing since.. Glyphs.
Post Reply