I think I know the meanings of \baselineskip
, \lineskip
and \lineskiplimit
in TeX, I also know \baselineskip
, \baselinestretch
, \linespread
and the second argument of \fontsize
in LaTeX. However, I get confused when I meet the phrase 'double spacing' and setspace
package.
The question is, which dimension is doubled? Is it \baselineskip
, or the skip between bottom and top of the two lines (something like \lineskip
), or some dimension else?
I read the article about
leading
[1] in Wikipedia. It seems that the original meaning of leading
is \lineskip
. In Bringhurst's book (The Elements Of Typographic Style), \baselineskip
is called a basic leading, total leading, while \lineskip
is the added leading, but they are never doubled.
In LaTeX, the basic total leading is the second argument of \fontsize
, which is set to \baselineskip
. For example, normal font size is 10pt with 12pt of \baselineskip
. So, does double spacing mean \linespread{2}
? Or it implies a 10pt + 2x(12pt-2pt) = 14pt of TeX's \baselineskip
, say, \linespread{1.16667}
?
Microsoft Word tells me it should be the former. 'Double' line spacing means \linespread{2}
in LaTeX.
(In word, font size 10pt, single spacing gets 12pt baseline skip; double spacing gets 24pt)
setspace.sty
tells me both are wrong. \doublespacing
is defined as \setstretch{1.667}
. (The value is slightly changed to fit different \baselinespace
)
That is to say, 'double spacing' means the baseline skip is double length of font size. (1.667x12pt = 20pt = 2x10pt.) Why?
(Using setspace
, font size 10pt, \singlespacing
gets 12pt baseline skip; \doublespacing
gets 20pt)
The more I read, the more confused I get. Can anyone help me to clarify the concept?
I do find the discussion rather pointless. The old doublespace
package decided that "doublespacing" means twice the \baselineskip
. setspace
decided that "% one and a half spacing is 1.5 x pt size
" and "% double spacing is 2 x pt size
". Perhaps the author of setspace
thought that as double spacing is already bad enough this would minimize the damage. Whatever is the reason of the settings in setspace
: If you want other values, it is easy enough to adjust them.
setspace
's existence is the fact that most, if not all US universities require theses and dissertations to be "double spaced". They don't define it, and they know absolutely nothing about typesetting, but they do check that your thesis meets their crazy requirements. setspace
's doublespacing option meets those requirements. So it's operationally defined. - Alan Munn
\linespread{2}\selectfont
or \setstretch{2}
or \doublespacing
, if I am asked to typeset a double spaced thesis, and the ones ask me know nothing about TeX (and typography) at all. - Leo Liu
setspace
defined a different version of double spacing
, but those who ask for double spacing documents may be satisfied with both \setstretch{2}
and \doublespacing
, although they're different. - Leo Liu
I'm pretty sure the origin of 'double spacing' is from the time of mechanical typewriters. I've learned touch typing on my mother's machine: You had a "carriage return" lever that returned the carriage (so that you could start at the beginning of the line again) and that at the same time moved the paper (in two distinct steps) forward to the next line. Since one of those "steps" is half a line, you could produce both 1.5 line spacing and double line spacing. In this sense 'double spacing' means doubling the distance between the baselines.
I had this discussion once with a friend who had a printers education (Sorry, don't know the right english term). I don't remember the details, but basically she said that the setspace
package doesn't calculate the line spacing correctly by it's universally defined formula. According to her, \linespread{2}
sets the spaces correctly. However, I myself prefer setspace
while working with a 1.5 line space, because I think it looks better. Maybe that was also the authors' intention.
(I would be happy if a more sophisticated answer comes along .)
\baselineskip
.setspace
defined a strange, but maybe widely used version. I would suggest my friends to usesetspace
package with\setstretch{2}
or\begin{spacing}{2}
for 'precise' double spacing if required. - Leo Liusetspace
got it "wrong." - TH.