Should a dot or period (.) get italicized?

Question

When do we italicise the dot (.) or period symbol, does it actually change the (.).

So, is

.

different from

.

Can anyone tell just by looking at the example which one is italicised? And does it matter? Same for colon (:) and an underscore (_).

---

Update

To all answerers, thank you very much. I am sorry, I am not very good at expressing my doubt. Actually, I want to ask, if I am making a font, should I make different glyphs for normal dot and italic dot, (and for semicolons and underscores)?

Answer 1

Italicized? Depends. You first have to understand what an italic is.

There is a true italic where letterforms are based on handwritten letterforms. There is oblique or fake italic where the roman letterform is slanted. There is a faux italic when a browser needs to render a italic, but a true italic is missing, than the browser can create a faux italic by slanting and scaling the roman.

Does a dot or period (.) get italicized?

True italic: The type designer will design and draw punctuation marks to go well with the italic character shapes. So most of italic punctuation marks in true italic fonts are different from the roman. A: (Most likely) different.

Oblique: If a type designer converts roman letter shapes into a oblique by slanting all shapes, then yes, the dot and all other shapes are slanted. But the designer may choose to alter some glyphs as he sees fit. A: Different, exceptions may occur.

Faux italic: The browsers code responsible for converting the roman into a italic will transform all the characters with the same matrix. A: Always different.

All this matters if you care about typography. At small sizes it's hard to tell the difference between dots. Most people won't ever notice. More people will notice if it goes wrong!

UPDATE

Most roman and italic fonts within the same family have different punctuation shapes. This is because the design principle (concept) of the roman or italic dictates the shape. True italics are based on handwriting. Oblique is based on the roman font and transformation matrix. If a principle is applied than all glyphs will look different.

Yes, design different shapes. Yes, you have the freedom to make exceptions. It's not wrong to copy some roman punctuation into a italic font. When it looks fine, it is fine.

Answer 2

Yes, it matters. In many fonts the italic period has a different shape than the normal period. It might not be visible at small sizes, but at large sizes the difference is hard to miss.

In order to find out which fonts italicize the different punctuation marks, you would have to investigate each. However, in most fonts everything, even quotation marks and the like, are italicized.

Answer 3

Can anyone tell just by looking at the example which one is italicised?

At 100% zoom, it's virtually impossible. But at 500%...

As stressed, such italicization has substantial influence when at a larger size.

Answer 4

Another way to think about this,

What if the text is changed so it is bold rather than italicised…

What if the text is changed so it is bold rather than italicised…

This may be a single change for someone to make with a style sheet or otherwise, they could reusability expect the text to still look correct.

Therefore I think it is important in lot of cases to end the markup at the correct place even if the result looks the same.

Answer 5

Here is a composite screenshot showing how the "FULL STOP" character is defined in Droid Serif Italic (black outline) and Droid Serif Regular (red outline). I took two screenshots from FontForge and combined them in an image editor, taking care to align the character coordinate systems.

In this case, you can see that not only is the italic period not quite the same shape, it's also going to be placed differently with respect to the characters around it. That can readily be seen at this 100% screenshot of 72pt text taken from Libre Office Writer. In the first sample, the full line is in Droid Sans Italic; in the second sample, the letter "l" is and the "." is in Regular; and in the final sample, the full line is in Droid Sans Regular. Since "l.l" is not really a well-motivated piece of text I don't think your aesthetic reaction (or mine) to this sample should say too much about whether it's "good" or "bad", but it certainly shows that the different bearing in the two fonts is important.