Are there any rules, formulas or tricks to working out the correct width for the space character. Or is it a question of trail and errpr to see what fits best.
R ; )
I always give the space the same width as the i (including sidebearings). I don't think there is a rule for it.
Should the space character be differnt across weights then, form looking at other fonts I thought the space character was the same for the whole family.
My thumbrule: the innerspace of lowercase n. That means more wordspace for lighter cuts and less for bolder, as it should be ; ).
Having the space as a character is a relatively new phenomenon. To me, the space character should be established so that ragged composition (i.e., no justification) looks right. The space may well need to be different for roman and italic, depending on the letterforms themselves, and their sidebearings.
As a for-instance, I just made an OpenType version of Bembo from a Type 1 PostScript font. Among the many changes, I changed the space in the roman font from 258 units (1,000 unit em) to 220 units, and the italic from 250 to 200. The reason it wasn't done earlier was simply that our old composition system did not take the space from the font. A bold font would likely need more space, at least, when used at the same size as the text, in text setting.
Further, the wordspace (however derived) usually needs to be relatively smaller as you increase the size of the type. Obviously, you can't make this provision as a type designer, but must rely on the compositor who uses your type.
Word spacing varies with font, even within families. There are no absolute rules in the digital era. You may start with something around 250 units but the idea is to create a spce wich will make the word break clear enough without making the line fall apart. Word spacing tends to agree with letterspacing mostly. If the letterspacing is tight, the the word spacing is proportionally tight as well. Like much else about type design, the eye is the master tool.
I tried Berts' method of using the inner space from the lowercase "n", but I'm getting very ugly rivers running through blocks of text, could this be an indication that my character spacing is incorrect
Historically. The space character is one third of the Em or one half of the En.
As long as your history covers about 1880 to about 1940.
When you hand-set type (1450+ to whenever), you start with the smallest space you are willing to use. To justify the line, you add space. Life is tough enough without starting with a larger space & having to take it out.
The machines came in right about the time when wide wordspacing was in fashion, which is where you get the "thick" (3-to-em). And by-the-way, Linotype linecasters weren't on an em system, you had a choice of "spacebands" you could use. The "thin spaceband" went from about 2 points unexpanded, to about 5-6 points fully expanded. A good Linotype compositor could tell how much a space would be added to a line, & would hyphenate a word so the spaceband wedge wasn't fully used.
As to your rivers: Maybe. If you are using words all the same length - 3- 4- 5- letters long, you're going to get more rivers. If you are using a text that could occur naturally, you'll get a better feel for how the space is working.
One more thing about "history." In the 19th century, many fonts tended to have a wider set than the current fashion, so perforce the space needed to be bigger. You will also get a different feel to the space depending on your leading and margins. One thing far too few book designers seem to realize is that there is a relationship between word space, leading, and margins (which of course, implies measure, given standard paper sheets).
Obviously, the type designer cannot provide a correct space for all settings. But if it is a text font, you could not ignore text, that is, 8- to 12-point settings.
Life gets much more difficult for a display font, because things that will affect the wordspace include size, but even the number of words in the line. For example, if you are setting subheads in small caps, the amount you letterspace will be a factor of how many words are in the head. Try it. Set "the next one" in small caps & get it right. Now try that letterspacing & wordspacing for "machinery gone amuck in the twentieth-century industrial plant" I guarantee you, those values will no longer look right.
"As long as your history covers about 1880 to about 1940."
RachelR was looking for a rule. I can't vouch for all the traditional fonts published but Helvetica is based on that rule. Obviously with todays technology you can go in any direction you want.
Yes, the space width should be the same for all weights, as should the tabular figure widths -- because they are required to work together occasionally in tabular settings.
I thought that was what the figure space (U+2007) was for?
Nick, I don't agree. I don't feel you set up a font to it's disadvantage only to cover one possibility. As for tabular setting, you can always use the italic or bold commands around the numbers only, without the spaces. That would preserve the spacing (usually roman) throughout the table. While I can't think of situations where this wouldn't work, you can always just use another tab stop in the table if push comes to shove.
The other side of the coin is that you often have italic text run in with the roman. Why have unfortunate spacing here? And you can't change, say, the spacing for just the italic in an application program such as InDesign, since that spacing (min-ideal-"max") works on the entire paragraph, right?
I usually start with the width of the lowercase i, and then adjust it by eye (most often making it narrower).
An average, across a wide range of typefaces, is about 1/4 em. Very very few typefaces have a space as big as a third of an em. This is true even in hot metal typefaces (Lino/Mono).
Heavier weights typically have thinner spaces (not wider, and not the same).
Of course, some type designers today may have varying ideas, but this is what many great type designers have done over the last century or more.
I stand corrected. I should have said that the space character should be based on one fifth to one quarter of the Em.
that's about what I found when researching spaces.http://www.microsoft.com/typography/developers/fdsspec/spaces.aspx
nothing was less than 1/5 the em and usually regular weight fonts were 1/4 em. Expanded fonts tended to be wider widths than others, as ~1/3.
many traditional space characters are no longer necessary since applications layout engines add and remove white space automajically. The thin space which use to be available in font before PostScript has disappeared but is in Unicode (because it was in some character sets historically)
Charles, I guess I should preach what I practice! -- I looked at a variety of my faces, and the space width varies with the individual font in most of them.
Frederic Goudy suggested the width of a lowercase i. That would be the visual width, not as, with metal type, the width of the body. Of course, if you've ever looked at Goudy's typesetting you can see how this is simply wrong. Nevertheless, I always recommend it as a starting point to my letterpress students. Keeps them on the right track. It's easy to see when the width is too narrow, not so if it is too wide.