The "Kerning" Issue (no doubt - CBS documents were kerned)

http://www.rainabear.org/Journal/Entries/0904/11.shtml ^ | 9/11/2004 | RainaBear.org

[supercat]

So the blogger is making a valid point even if she has asymetrical positioning of the letters confused with kerning. It rules out all the other kinds of type writers outside of the Composer I suppose.

No, since typewriters could have characters assymetrically positioned. What few typewriters could do is move the carriage by variable amounts after each character, and what no typewriter could do, at least without ridiculous amounts of pointless finagling, would be to move the carriage just the right amounts to match Microsoft Word's default spacing.

[supercat]

Don't trust just any info on the web you can find. They confuse (close)letterspacing with kerning, but these are different things.

Perhaps "kerning" would have been the correct term when dealing with lead type; certainly it does not match modern usage.

The documents cited to not exhibit what would be called "kerning" in the modern usage. There are some slight overhangs, but such things can exist even with typewriters (note the Courier New examples above). The giveaway is not that the document is proportionally spaced, but that it happens to match Word's default behaviors so perfectly.

[eclectic]

Yes, Times New Roman is "proportionally-spaced" font, meaning glyphs (characters shapes) have different "advance widths", with "overhangs", meaning that some glyphs have negative "right offsets", meaning that the next glyph is normally placed closer than the advance width of the previous glyph.

If you want to go even more technical, Times New Roman does support kerning, but as an optional feature, which is by default off in MS Word. Again, technical definition of "kerning" is adjustment of glyph positions for specific pairs of glyphs in addition to normal positioning (which might have overhang) Here is a demo: open Word, change zoom setting to 500% and type "f". Observe where the caret blinks - it is in the midst of "f" glyph, shifted by the "advance width" of "f" from the beginning of the line, which is less than the full width of the glyph (which inludes the overhang). This is the normal position where the next character will be placed. Kerning would adjust this position further, but only for specific glyphs. For "f" kerning is actually not needed, but it would be useful for "W" followed by "o", for example (you can use Format Font dialog to turn on and play with kerning)

[over3Owithabrain]

To everything, kern kern kern....

[eclectic]

Err, let me correct myself in the interest of full disclosure :-)

negative "right offsets", meaning that the next glyph is normally placed closer than the advancefull width of the previous glyph.

[rainabear]

I've just addressed this on the updated page:

http://www.rainabear.org/Journal/Entries/0904/11.shtml

The upshot of it is that yes, f does have an overhang. However, a does not (and neither does t) and those are the letters that are used in the example. So an overhang can not account for the difference in widths of the at ta pairs.

Also, I typed the same sentence twice in word and turned kerning on for one of them. They look exactly the same. My conclusion is that Times New Roman must be kerned automatically.

Therefore everything I said in the original post is completely accurate, unless you want to call what it's doing something other than kerning. But that doesn't change the fact that the f and the a are closer together in af than they are in fa, and that Word and the memo do both these things, and that this isn't something you'd find on a typewriter.

[rainabear]

Make that:But that doesn't change the fact that the t and the a are closer together in at than they are in ta.

[eclectic]

I just checked in in Word and I see that the difference between at and ta is really very small. I think the apparent difference in your picture is just a result of bad copy. In any case the fundamental assertion that difference between, say fo and of (which is easily observable) is due to kerning is an incorrect use of terminology. This is not due to kerning - this is just because f has right overhang, which not the same as kerning.

The assertion that Times New Roman is "kerned automatically" is incorrect. See my explanation in the posts above

Look, this is a huge deal and let us be extra careful.

[LTCJ]

F-overlap and kerning BUMPmark.

[rainabear]

Yes, the difference between ta and at is not all that great, but it is there. Bad copy? I did a print screen, which is all digital, there shouldn't be any mistakes added like if I had printed and scanned it or anything. Photoshop did add some blending when I increased the size, but that's done according to a very exacting mathematical equation and doesn't change the beginning and end of the characters horizontally. From the pic it is obvious that there is a clear difference between the pair. Don't trust it with smudging? Here it is again without that:

And look, the top pixel of the a tail is clearly underneath the cross bar of the t.

The a and t letters don't any have overhang like f does.

So if it's not technically kerning, it's still something, whatever the technical name of it is, that's making those letter pairs different sizes.

[eclectic]

So if it's not technically kerning, it's still something, whatever the technical name of it is, that's making those letter pairs different sizes

The technical name for this is "character metrics" and they can be the same for an IBM Composer font. My point is that this is not a clincher...

[FranceForBushInAustin]

Kerning algorithms were added to MS Word in 1981.....

[AndyJackson]

In order for the type to overlap, the center to center spacings between type blocks must be less than 1/2 the width of the two blocks. First this requires proportional spacing, and second, unless your typewriter has memory the designer cannot allow this, because you must have kerning or you cannot guarantee that you will not get overlap of typed characters (i.e. you must have knowledge of kerned pairs).

[rainabear]

I'd really like to understand this. I find no reference to character metrics on this site with the Composer manual.
http://www.ibmcomposer.org/SelComposer/Manual/toc.htm
What I do find, in the appendix, is a list of characters and their respective relative widths. - an A is 8 units thick, a l is 3 units thick, etc. This is how it does porportinal spacing. I assume that, combined with how the letter is centered in its block, and how far the machine advances with that letter composes character metrics. Right? There's no mention in here of variable character metrics depending on the next character, which is what you would have to have to do what we are seeing, right?
Also on this page, http://pfaedit.sourceforge.net/editexample5.html which talks about character metrics, it says under kerning:
If you are careful in setting the left and right side-bearings you can design your font so that the spacing looks nice in almost all cases. But there are always some cases which confound simple solutions.
Consider "To" or "Av" here the standard choices are inappropriate. The "o" will look better if it can slide more to the left and snuggle under the top bar of the "T". This is called kerning, and it is used to control inter-character spacing on a pair-by-pair basis.
In the example I posted, the a snuggles under the bar of the t, which is exactly what he is saying.
Either way, the width of the at and ta pairs in Word and the memo are the same and there is overlap between the tail of the a and the bar of the t. In the example of text someone posted on an IBM Selectric Composer, which is the typewriter all the apologists say could have typed the memo, there isn't overlap. This is because the a doesn't have much of a tail, which is why the Press Roman Font has similar spacing to the Times New Roman font, because it doesn't have all of the serifs to deal with that TNR has.

Whatever you call it, it's there in the memos and word, and it's not on the text from the Selectric using the Press Roman Font where someone tried to copy the memo, and got close, but not close enough.

[eclectic]

Yes, the differences are there, but they "can" be explained away by the poor quality of the copy (which can eliminate or extend serifs in either case, and even produce more severe distortions). I think all the experts agree now, that the most damning thing is the exact match of the whole text to MS Word. While each single feature of the memo can be explained away, let it be even in a rather implausible way, it is against all odds that all features "conspire" to match MS Word

Character metrics is computer terminology. It just refers to parameters describing a character, its width, bearings, etc. In particular different characters have different bearings from left and right. They are responsible for the effects you observe, there is no evidence of kerning (in precise, computer technology sense of the word) in the 'docs'.

[supercat]

In order for the type to overlap, the center to center spacings between type blocks must be less than 1/2 the width of the two blocks. First this requires proportional spacing, and second, unless your typewriter has memory the designer cannot allow this, because you must have kerning or you cannot guarantee that you will not get overlap of typed characters (i.e. you must have knowledge of kerned pairs).

Perhaps your Courier font is different from mine, but on my computer the two "M"'s in the Courier New sample definitely touch each other, and there is definite (albeit slight) overhang on the characters in the second column.

To confirm this latter point, select characters individually and note that each extends just past the edge of its selection box. Given that the selection boxes are directly adjoining, this implies that they overlap (albeit by only a pixel or two).

You are correct in your statement that kerning is necessary to allow characters to reach beyond their escapement boxes without any possibility of overlap, but because characters CAN overlap this is generally not a major issue. Unlike lead type which can be damaged if character glyphs overlap, computer type has no such limitations.

[supercat]

While each single feature of the memo can be explained away, let it be even in a rather implausible way, it is against all odds that all features "conspire" to match MS Word.

Bingo. This is the point which needs to be hammered home. If someone had a photo of Einstein standing in front of a blackboard on which were written the numbers "9911 2198 0725 2194", the photo would have to be a fake produced after 9-10-04, and almost certainly after 9-11-04. While in one sense, that set of figures should be no less likely to have been written than any other set of random figures, the likelihood that Einstein would happen to write out the numbers for four consecutive future Pick-4 drawings is basically nil.

The question is not whether someone in 1972 could have produced a document with the particular font metrics used, but whether it's plausible that anyone (or, more specifically, Mr. Killian) would have done so.

[Samwise]

Those were the days, my friend. All of this has reminded me of how much I love Word.

http://commfaculty.fullerton.edu/woverbeck/dtr5.htm

[Alouette]

Hmm, people on these threads have been using the term "kerning" when they are really referring to the spacing offset that is a special feature of TrueType fonts, which were not invented AND PATENTED until the 1980's.

The definitive, last-word, final-nail-in-the-coffin from a typesetting expert

Includes the technical definition of "kerning" which I was surprised to learn is not a default in Microsoft Word. However he then goes on to say that the infamous "CBS memos" were made using TrueType fonts, even more damning than "kerning."

[rocklobster11]

This is excellent, thank you! I've been looking for some type of proof-positive that there was kerning in the "documents".

I did a similar exercise with the letter "f" which has a setting as a computer font that causes it to overhang the next letter. See:

What's the Font, Kenneth?