Kerning & Mortising Type

REPRINTED FROM TYPE & PRESS / COURTESY OF the APA

By Fred Williams
Editor & Publisher, Type & Press
Spring 1992

Since the earliest days of printing, compositors have been cognizant of the fact that any variation in the spacing within a word may impede the reader as his eyes move across the line of letters.

An eye reading a book might be compared to an auto traveling down a road; if the highway is straight and smooth, the car will speed along unhampered. A twisting, rough road will probably slow down the journey. Likewise, the eye will move swiftly down a line of characters if the letters and word spaces appear uniform. It will quickly assimilate the author’s thoughts. But the eye and the brain will be slowed down if the rhythm of the texture of the line is erratic.

The symbols which make up the letters of our alphabet come in various shapes—square, round, triangular, horizontal, vertical or a combination of these. When these symbols are combined to form words they may nestle together like peas in a pod or remain far apart as though one had bad breath.

Apparently Gutenberg recognized this problem and created many logotypes (two or more letter combinations linked together on a single piece of type) that appeared more like the tightly connected letters drawn by the medieval scribes.

Printing historians believe that the father of printing may have designed and used a large number of separate characters for his alphabets. To avoid irregular spacing he created identical char- acters in many set widths!

But over the centuries most printers gradually ceased using logotypes because of the problems of maintaining large sorts collections and the additional time required in the setting of them. Eventually each piece of type carried only one character. But the f ligatures (fi, fl, fl, ffi and ill) were needed and useful and have survived.

A majority of the symbols of the lower case alphabet share a common x-height. The others have projecting ascenders or descenders. The letters may vary a great deal in width. Each lower case character has a unique shape and when they are assembled into groups, each word has a distinct shape with a recognizable silhouette. This is the reason for the superior legibility of the lower case over all cap letterforms.

The lower case symbols are closely packed together to form words. To enable one character to be distinguished from the next one a minimum amount of white space is needed. Ideal word spacing should be about the width of the vertical stroke of a lower case “i” of the font. Except to separate an occasional “Siamese twin” letter spacing is seldom used as it may cause their silhouette to become less discernible.

The cap symbols have more consistency in set than the lower case and most are geometrical in shape. When they are combined into words they have a regular outline and are not as easily recognized as are their lower case brothers. In display typography this is an advantage over the irregular lower case forms. All cap lines are more read able if letterspaced slightly.

Top line: as type comes from type foundry.
Second line, type letterspaced equally to widest space. Third line, letters mortised to eliminate awkward space between letters.

Optical letterspacing came about when typographers mortised and spaced out type to the specifications demanded by advertising agency art directors. Mortising is the removing of spacing between some letters so that they all appear to be evenly spaced. A test to ascertain if the line is spaced optically correct may be made if the line or a proof of it is held upside down, so one is not influenced by the sense of the text, and the spacing examined under this neutral condition.

To obtain even letter spacing in caps two methods may be used-proportional or even. The first is suitable for roman faces in which the capitals are somewhat irregular in width. The task is to locate the two letters in the line which enclose the largest area of white space. Then additional spacing is added between the other letters until all letterspacing appears the same as this larger area. After equal spacing is achieved between letters additional spacing should be added between words.

The goal of the other method is to reduce the irregular gaps between letters by actually removing the metal between all the culprits who are too distant for easy reading.

In setting display sizes of type it may be necessary to mortise certain letters and points to obtain optical spacing. For high class typography it is a common sight to see symbols such as: A, F, L, P, T, V, Wand Y mortised in the larger sizes.

For instance when a capital L is followed by a cap T, an especially irritating combination is formed. To eliminate the excessive break between these letters a corner may be cut out from the upper right of the L and the corner from the lower left of the T so that the horizontal element of the T will extend into the open space at the top of the L, bringing the two symbols within speaking distance.

Other cap combinations that should be mortised include: TA, AT, PA, VA, WA, YA, etc. Capitals T, V, W and Y when followed by a l.c. round character without ascenders such as: a, e, o, r, u, w and y should be notched to bring them closer together.

To tighten up spacing typefoundries kerned many cursive and italic faces, allowing extended parts of the letters to overhang the body of type. These unique kerns usually are supported by the shoulder of the character next to it. But the kerns are easily broken during planing, proofing, distribution or the press run.

This breakage problem was eliminated when foundries began casting letters with long tails, particularly swash characters, in mortised molds.

Richard Hopkins of the Hill & Dale Private Press & Type Foundry of Terra Alta, West Virginia is a Monotype enthusiast and explains kerning as it may be done on Lanston’s machine:

“One of the most satisfying things about owning your own typecasting equipment is that you can adjust and refine sets and letter positions to far more desirable precision—something never at- tempted by typefounders who were, for obvious reasons, more interested in getting production out in the fastest time.

“It is an undisputed fact in cold type that you can have two things occupying the same space. It’s quite simple to set one letter on top of another, if desired. That’s obviously not the case in hot type, where we are actually involved in moving physical elements around.

“But it cannot be concluded that because of this one cannot get well-spaced type when working with hot type. It’s admittedly more difficult and time-consuming, but it definitely is possible.

“An implement one will find to be indispensable in the process is a Type Mortiser. These generally were not found in shops other than those of fine typographers. That’s why they’re not seen too often today. With this handy tool, you can literally ‘nibble away’ white space at the top of one letter and at the bottom of the next to achieve a tighter fit. American Type Founders used this process by offering “pre-notched” type with some of its finer faces such as Garamond and others.

“Having your own typecaster enables you to cast type to overhang the body and thus ‘kern’ in quite unusual ways. This is possible up to the limits of the mold and the ‘head’ or ‘bridge’ of the machine which restrict lateral movement of the matrix over the mold opening. With the 72-point Caslon 437 ‘Newsletter’ shown below, it was possible to kern the swash N 20 points. The mold face drops away at that point. If greater kerning is at tempted, an opening under the kerning portion appears, allowing metal to escape and causing a big squirt. To the left, one can kern the letter about only 14 points for the same reasons.

“I have seen some absolutely horrible composition in hot metal where swash characters are concerned. I was determined not to repeat the errors when casting type for the nameplate of my publi- cation for the American Typecasting Fellowship. You will note that I cast all letters on very tight sets enabling a more desirable fit. I cast the swash N to a maximum of 20 points kern to right. Then I cast the lowercase e to kern to the left the maximum of 14 points. That’s how the e ends up a full 34 points to the left of the end of the swash, right where it should be in my estimation.

“Indeed, tight-fitting, good-looking work can be done in hot metal. But for this guy, who earns his keep with digitally previewed photocomp, I know which is the fastest and easiest process.

“Even still, working with hot metal provides more satisfaction. When they invented digital type, they made everything a lot easier, but they sure took the fun out of it!”

Because they cast a whole line at a time, slug casters: Linotype, Intertype and Ludlow could not cast kerning letters. To satisfy the demand of fine book printers, Linotype and Intertype cut a series of roman/italic two- and three-letter logo types to eliminate objectional wide white space between certain letters.

For many of its bookface designs Linotype punched matrices of closely linked pairs of characters. Called Typographical Refinements, these assortments include roman and italic logotypes with kerned periods, commas and hyphens. Some of these fonts made available over 60 tightly linked logotypes. They could be run in a side magazine or transferred by hand to the assembler.

Kerning and mortising may be thought to be exclusively cosmetic but actually it is an aid to read ability. It improves a page of text color in that all lines appear to have identical spacing, giving an even color to the page. But the reader, unless he is a skilled typographer, seldom realizes that it is kerned copy he is reading. It is claimed that it does little to improve reading speed or comprehension of the author’s thoughts. But for those who care to take the time, it’s well worth the effort, say many typographers.