http://en.wikipedia.org/wiki/Sentence_spacing

A similar approach could be used on the Web but I’m not sure it’s really worth the effort. Perhaps I’ll make a plugin once I’ve finished my flux capacitor.

Destry – I think we’re at cross purposes here. I’m talking about spaces between sentences (width) and you’re talking about line spacing (at least that way we both get to be right).

For one thing, there are usability studies showing that more spacing than just single spacing is easier to read. I’m a web user and this is definitely true for me. Your web copy here looks to have about a spacing of 1.5.

Also, there is no “line spacing” element or attribute in HTML, so when an author sees a WYSIWYG button in a rich-text web editor to double-space lines, the button is selling “line height” under the false print terms.

Line-height is quite variable in HTML, and for good reason; browser inconsistencies, differences in font design, differences in font rendering behavior at different sizes, and so forth.

Also, there’s this thing called “inheritance” in HTML/CSS where child elements can be defined one way (e.g., line-height) which in turn will be influenced by an attribute set on the parent (e.g., font-size). So a font having a font-size set at 11px will have a different line-height set at 1.5 than one that has the same line-height on a font size at 14px, for example. Things become extremely relative.

And there’s that usability thing I mentioned. While I agree that the equivalent of “double” spaced line-height is more than necessary, I do believe that 1.5 should be a minimum no matter what copy, website or font size.

I generally set the line-height at 1.5 (or use units when it involves list item heights for specific presentation) and things work out OK.

Another reason not to do it, and a reason why my failure to break my double-spacing habit, despite best efforts, doesn’t punish the reader.