Should roman and italic tabular figures have the same width?

Raphaël Ronot

The instinctive answer is yes...
BUT, in instances where the italic's design is much narrower than that of the roman, forcing the italic .tf to have the same width makes them awkwardly large and/or loosely spaced compared to the rest of the glyphs. 
I'm curious to know your position. Do you sacrifice æsthetics for the sake of italic-roman compatibility? Or do you generally don't care and go for a more harmonious design?
Thanks in advance

Craig Eliason

Yes, tabular figures should have the same advance width across the roman/italic divide. 

In the case you mention, I might be likely to make the proportional variants the default. 

Mithil Mogare

Italics are 7-15 degree inclined as well as it is 8-10% compressed to regular design. You can check more info here.

John Hudson

Aside:

Italics are 7-15 degree inclined as well as it is 8-10% compressed to regular design

While traditionally italics are have been narrower than roman, reflecting the natural compression of more quickly written forms, these days there seems to be a trend towards less condensed italics. I suspect there are a couple of, related, factors influencing this: the increase of reading text on screen, and the increase in use of sans serif type for text. Considerably narrower italics are now a stylistic cue to oldstyle serif types of renaissance and baroque models; whereas, most later styles of type are exhibiting less condensed italics.

In my Brill family, the italics often end up setting wider than the roman.

Mithil Mogare

these days there seems to be a trend towards less condensed italics. I suspect there are a couple of, related, factors influencing this: the increase of reading text on screen, and the increase in use of sans serif type for text. 

Also I want to add that I have seen some typefaces where they have continued the italics without changing letterform such as a and g. Is it because of trend or any other reason?

Raphaël Ronot

Thanks for your insights, ugly-but-compatible it is then  

Mark Simonson

Not changing the /a and /g in the italic was the usual practice with sans serif italics until the last twenty or thirty years. There are examples of serif faces, mostly around 1900, that did this, such as Bookman and DeVinne, but it's pretty unusual.

Nick Shinn

Yes.
There are certain kinds of document in which both roman and italic tabular figures are required. A quick search found this:

Mark Simonson

Interesting example, Nick. The italic tabular figures match the width of the roman figures, but they didn't align the decimal points or display the same number of digits after the decimal. Weird.

Nick Shinn

Possibly because, in a spreadsheet application, it’s relatively easy to make text in every cell flush right (the default), but an extra step to format “tab alignment” within a cell. 

Raphaël Ronot

Related question: is it also true for regular <> bold?
In other words: should *all* tabular figures of a given typeface have the same width? — unless of course if the family has compressed or extended styles.

Craig Eliason

Raphaël Ronot said:

Related question: is it also true for regular <> bold?
In other words: should *all* tabular figures of a given typeface have the same width? — unless of course if the family has compressed or extended styles.

Some discussion of that in this old thread.

Raphaël Ronot

Thanks @Craig Eliason!