I've been looking into legibility issues and some such characters which quite easily can be made explicitly unmistakable. When looking at slashed zero variants there is a chance of replacing one confusable character with another by adding the slash or dot (found
this to be an informative paper).
Is there a reason why slashed zeros are not more commonly drawn with a downstroke (like in
this font, for example) and instead the variant with the slash is used that resembles above all else the slashed O and empty set / average sign? It seems to me ironic that a feature intended to reduce letter identification errors might actually increase them, so I was wondering if there is an equally problematic catch with the downstroke I am not aware of.
Comments
I say modern slashed zero, because there are manuscript slashed zero examples dating from the first century of introduction of the zero into Europe. See page 5:
http://tiro.com/John/SameDifference2-DECK.pdf
BTW that Bigelow piece is great but it's missing arguably the best general form of OS zero: weighted only on one side (with my preference for the left). See the one in Whittingham.
Concerning your point above, I would say maybe humanism doesn't have to be so shackled by one particular –not to mention obsolete– marking device...
I personally have never seen an predefined code to be copied or entered by someone* that might either contain Greek Θ or Ø, and thus the slashed 0 is usually perfectly fine. It differentiates it from the uppercase Latin O and that’s all that is needed in that situation. This might be a little less perfectly clear in Greece / countries using the slashed O in their language, but as mentioned by others, there are further considerations like pen logic that play a role, too.
*which is imho when this kind of legibility is really important.
An "unrealistic chance" can creep up on you... Although it's rarely worth sacrificing too much style for a remote possibility of confusion, the question here is about how to best alter a regular zero for extreme cases. Why would a potentially confusable forward slash (or dot) be preferable to a non-confusable backslash? Pen logic? How many people complain about the diagonal of the conventional contrasty "Z"? Rather than being overly sensitive towards an imaginary marking device I'd rather be sensitive towards actually existing Greeks, Swedes, etc.
BTW "all that's needed" generally leads to things like Arial...
I would agree that in contrast rich humanist faces the weight of the stroke in the reversed orientation might become too heavy - then again you could ask if a special version of zero does not do that either way?
Good to see, however, that no obvious reason has been listed not to use this version of a slash zero in other cases, and that, in fact, it's not as uncommon as I suspected. Thanks for your input!
I would think the relevant question is when in history did contrast get added to harmonize it with the rest of the written/typographic figures?
(Which then necessitated strategies for differentiation from Oo in certain contexts.)
In any case it would be interesting to learn the history, but I can't discern how it might help actually design it for the living.
The illustration used there is from G.G. Neill Wright's The Writing of Arabic Numerals (1952).
This means that sequences such as 606, 908, etc., and of course 00, would have have formed nasty clots, in the normal angled stress—and 1100 been extremely uneven in colour, especially considering the monowidth (“tabular”) constraint—had the zero been rendered like the letter “o”.
Another style violation—reverse contrast (e.g. in Stempel Garamond) also addresses this issue, but has never caught on.
And the contrastless zero is not totally odd, as the oldstyle four also has thin strokes going in different directions.
When one considers the way the thick and thin strokes are distributed in the classic oldstyle figures, and they way that numbers comfortably differentiate (in monowidth) in mixed case setting as being slightly “tracked out”, the design of the oldstyle figures, including the circular, mono-thickness zero, is really a very clever system, and much better than the didone.
You mean like "book"? :->
Instead of making a really bad zero, let's fix deeper. After all "6" and "9" are even more confusable than with zero.
Compare <9-letter_o-6> with <9-zero-6>.
The fat part of the long strokes of 9 and 6 coincide with where the join is, close to the extremum.
And on a purely semantic level, the negative centre of contrastless zero, its round nothingness, is promoted above the value of its positive component, which merely defines a boundary with minimal presence, and is not thus the trace of pen strokes.
I'm a huge fan of differentiation, I just think there are more clever –and less distracting– ways, like giving only the zero horizontal contrast.
In the end... having an alternate for the zero so one can have it either way (monoline or conventional stress), that would be great!
In display work, oldstyle is rarely a good option.
Now for something completely different, is it normal for a slashed zero to have the slash strike through the glyph like in /oslash? I'm used to slashed zeroes where the slash doesn't cross the body (most monospaced fonts). To me a slash extended beyond the oval looks like an error, a grave one. It however happens in some fonts, now I observed it in Linux Libertine.
Edit:
I looked into the document John Hudson provided, and page 5 suggests a strike through zero can be justified historically... I'm still not fond of it.
Secondly, in mixed case setting so much depends on the particular number. 1960 is always a good year, but 100% doesn’t carry its weight.
And of course, the issue of how much zero looks like the letter “o” is magnified.
I also don’t like “f” ligatures in display settings; nuances designed to help difficulties disappear in the flow of small text have the opposite effect in display, with their mechanism laid bare.
I agree with Adam, the slash extending past the zero's round outer shape looks like a mistake. The historical handwriting examples showing slashes through the zero that extend beyond, and that's speculation on my part, might just be the expression of swift pen flow. Confusability with ø was likely less an issue than it is now in our multilingual information society, and typefaces that cater to its demands.
Since I've been paying more attention to this, I've also found examples of slashed zeros with a horizontal stroke (or even just a centered dot). In my opinion that, too, replaces one confusability for another, by making the slashed zero close to theta.