dns@sq.uucp (David Slocombe) (10/21/88)
In article <224@dcs.UUCP> wnp@dcs.UUCP (Wolf N. Paul) writes: >I should also pass on what some have pointed out to me: in the traditional world >of movable (lead) type, point size refers to the height of the slug on which >the letters of a given font are mounted, not necessarily to any measurable >feature of the printed image. Thus, you could have tiny characters mounted >on a 28pt. slug and it would be considered -- technically -- a 28pt. font. Not so! I worked for many years in a hotmetal environment at a large metropolitan newspaper, much of the time hacking at a typesetting program that drove (via paper tape) some 16 "linecasters" which produced the lead slugs you are referring to. I can assure you that there was never any confusion in anybody's mind between the size of the slug and the size of the type. Hotmetal technology did not change significantly from the time it was invented in the 1890s until its demise in the 1970s, except for the addition of paper-tape interfaces in the 1950s which worked like player-pianos (the keys actually "bounced" as the tape was read). We would say, "Set this 8 on 9 in 11 picas nut and nut." That meant: typeset it with 8-point type on a 9-point slug that was 11 picas long but with an en-space at the beginning and the end of the line. In troff terms, that's: .ps 8 .vs 9 .ll 11P-1n .in 1n (Actually the slug, as cast by the machine, might be longer than 11 picas because of the mold being used, but it would then be "trimmed" with a rotary table-saw to the 11-pica length. That's right: sawing lead like wood! Actually it was a lead alloy, bright like solder.) The height (and length) of the slug was determined by the choice of mold installed in the linecaster. There were several molds available on each machine which could be selected manually by a mechanic, and the set of molds on a particular machine could also be changed by a mechanic, although it took a while. So you might have a mold that cast 9-point slugs 15 picas long. Or 10-point slugs 11 picas long. And so on. The actual type came from "magazines" of brass "matrices", each carrying the indented image of two symbols. The positions of the two symbols on a matrix were known as "on the rail" and "off the rail" (I couldn't explain the origin of those terms without a linecaster in front of me). All the symbols off the rail would represent, say, the Times Roman face, while all the symbols on the rail would represent the Times Italic (or, alternatively, Times Bold) face. A given machine could thus typeset in only two faces, both at a single pointsize, on a single size of slug. (There WERE linecasters, called "mixing", that could "change magazines" under manual or paper tape control, but they were relatively rare.) All the symbols on the matrices in a given magazine, both on and off the rail, were in the same pointsize. There was no relation between this pointsize and the height of the mold being used except that the font (magazine) pointsize could not be larger than the mold's height. The operating cycle of a linecaster was to "assemble" the matrices making up the words in a line, with "spacebands" (double steel wedges) between the words, then (if the line was to be justified) to force the spaceband-wedges together to expand the interword spaces so that the type filled the measure horizontally. Then move the whole assembly up against the one open side of the mold, and squirt hot lead into the mold. Then remove the assembly from the face of the mold and distribute spacebands and brass matrices back to their original places, and also dump the new too-hot-to-touch slug into the tray holding the growing "galley" of type. Then start over. To watch one of these machines work at 10 to 15 slugs a minute while the keys bounced up and down and uncountable moving parts clicked and clacked was a wonderful experience. ---------------------------------- When I wish to measure the pointsize of type I set a row of fjfjfjfjf, measure from the top of the f to the bottom of the j, add a few pixels for shoulders, and call that the pointsize. This is not strictly true but usually the most desirable measure in an electronic publishing environment, I think. The more correct measure, I believe, would be to set a row of hqhqhqhq and measure from the top of the h to the bottom of the q and not add anything extra. This is the real visual pointsize. But as the rounded part at the top of an f, for example, usually goes slightly higher than the top of an h in order for them to LOOK the same height, if you want to guarantee that, when you set lines "solid" (e.g. 9 on 9 or 10 on 10), the descenders of the one line don't actually touch the ascenders of the next line, then the "fjfjfj" approach is necessary. But keep in mind that the exact pointsize should not be taken too seriously anyway: the measure that really means something is not the pointsize but the x-height of the font. Perhaps Chuck Bigelow could be persuaded to comment... ---------------------------------------------------------------- David Slocombe (416) 963-8337 Vice-President, Research & Development (800) 387-2777 (from U.S. only) SoftQuad Inc. uucp: {uunet!attcan!utzoo, utai}!sq!dns 720 Spadina Ave. Internet: dns@sq.com Toronto, Ontario, Canada M5S 2T9
dik@cwi.nl (Dik T. Winter) (10/23/88)
In an excellent article <1988Oct21.134156.18568@sq.uucp> dns@sq.com (David Slocombe) writes: > We would say, "Set this 8 on 9 in 11 picas nut and nut." > > That meant: typeset it with 8-point type on a 9-point slug that was > 11 picas long but with an en-space at the beginning and the end of > the line. > > In troff terms, that's: > > .ps 8 > .vs 9 > .ll 11P-1n > .in 1n > That's right, the slug is always larger than the type itself. However, the difference between slug size and type size depends on the kind of script used. For latin, greek and cyrillic alphabets it is in general about 10-20 % (8 on 9, 10 on 12 etc.). For other scripts it is different, for hebrew we have: 8 on 14, 10 on 16, or even 10 on 18. For arabic it is again similar to latin. My question is now, if different scripts have to be combined, what must match? I think it is the slug size, and not the script size, so when I have to put an hebrew word in a piece of times latin set in 12 on 14, for the hewrew part I would use 8 on 14. However, arabic is still more difficult, as arabic 18 on 20 has about the same clarity as latin 12 on 14. So how to combine? -- dik t. winter, cwi, amsterdam, nederland INTERNET : dik@cwi.nl BITNET/EARN: dik@mcvax