A very demanding task, vital for the success of a typeface is that of finding the right spaces for each singular letter. As one can easily imagine the number of possible combinations even in a Roman alphabet is very high. But, what may seem frightening to someone making a quick calculation of that number is quite a daily business for a type designer. For the simple reason that he has got used to it and of course over the time found his methods to deal with it.
There are indeed several good methods for this challenge that didn’t change so much over the centuries of making typefaces, I guess. One of them is doubling letters to pairs or creating even higher numbers of copies and put them side by side. I remember the first time seeing something like that in an old book about, the famous American type designer and printer in the first decades of the past century. He used to print testing sheets of his metal casted letters into large rows of duplicate letters.
Doing so, in the first line, does give the type designer an idea of the general room (neglecting left or right side distances) each letter has been given. On the hand this is to avoid a too deep color caused by letters tightened too much, on the other it gives us a more precise control over the inner and outer rhythm of straight lines. In an ideal, admittedly a little too rigorous sense, distances between the two (or three) vertical lines within a letter image should be the same as the one between the last one of one letters and the starting one of its succeeding colleague (remember: for all possible combinations!). By putting, initially, the same letter in a row (at least, two of them) and glancing over them it is easier to detect eventual rhythm mistakes.
Having done so and given that the type designer knowing well his creation and therefor being able to center each individual letter image between its (invisible) borders he may then compare rows of different letters among each other. To settle if certain letter designs lack of sufficient space on left and right side or are set up to tight.
The next step is that of comparing more thoroughly typical letter combinations or the ones that each designer depending on his individual style and preference (of course being related to his mother language, but this would fill another essay much longer than this one). In my eyes it is also important to concentrate with this on pairings that one particularly is being fond of. What may sound kind of funny, is a design truth for my opinion. Because having fun with this work or let’s even say to fall kind in love with letter pairings and combinations is part of the success story of a typeface. For the creation process is far less theoretic or mathematic as one may suppose. Simply for the fact that it takes long time, asks a lot of patience of the craftsman or a digital designer and in the end is a matter of heart. This is when inspiration comes into the game. And changing it.
Personally I try to melt the glyph design process and the letter spacing to one continuous process. Like here in the Memoir ‘sa’ combination I also correct themany times after the first sketches to accord letters’ rhythm between each other. I try to intuit a certain flow that is able to chain the letter images together. In a way that also lines that cross the general rhythm of a typeface maybe be more easily handled by the human eye to fit into it. It is hard to exactly describe what this means but certainly it is also a matter of the (invisible) white spaces that place between two letters.
If you are working on a digital Metrics window you may also add and delete characters, go back and forth doing so to trick the eye a little and try to intuit what happens when they change places. Close the eye a little and concentrate on vertical rhythm only regardless of which letter the consisting straight line are being part of.
To be honest, in my eyes, it is kind of a fifty-fifty game. Learn about the methods and get used to them but also trust blindly in your own feelings. In the end we are not talking about reason here, we gain to achieve beauty.
(…) vedevo emergere un ovale bianco, degli occhi neri, degli occhi verdi, non sapevo se fossero gli stessi che mi avevano già deliziato un momento prima, non potevo metterli in rapporto con una data fanciulla ch’io avessi separata dalle altre e riconosciuta. E quest’assenza, nella mia visione, del distacco che avrei presto stabilito fra loro, propagava attraverso il gruppo un ondeggiamento armonioso, la traslazione continua di una bellezza fluida, collettiva e mobile.