- A leading space= whitespace in front of a printed word or text.
- A trailing space= whitespace after a word or at the end of printed text.
leading and trailing spaces in Microsoft Word
This idea of leading and trailing spaces comes from airfoil terminology where a wing on a plane is said to have a leading and trailing EDGE. The leading edge is the edge that faces into the wind and the trailing edge is obviously the other edge that does not face the wind and onto which the wind is swept over as the plane moves forward. I can't prove that but I can see no other origin from this idea.
BUT CAREFUL: In typography, leading (/ˈlɛdɪŋ/ LED-ing) refers to the distance between the baselines of successive lines of type. [taken from Wikipedia]
Pronunciation: A leading space is not the same pronunciation as leading, the distance between baselines of text. Leading is like the word metal. A leading space is like leader.
Example of leading from Adobe's InDesign:
Explanation from Adobe:
The vertical space between lines of type is called leading. Leading is
measured from the baseline of one line of text to the baseline of the
line above it. Baseline is the invisible line on which most
letters—that is, those without descenders—sit.
The default auto-leading option sets the leading at 120% of the type
size (for example, 12‑point leading for 10‑point type). When
auto-leading is in use, InDesign displays the leading value in
parentheses in the Leading menu of the Character panel.
leading from Adobe
Leading, the space from one baseline of type to another, is standard for a size of typeface: 12-point; 14-point, etc.. BUT: you can increase and decrease it for effect. Most people think that in Microsoft Word only the number of line returns will increase or decrease white space between lines. That is not true. You can also increase and decrease the leading but Microsoft no longer calls it that. They call it: line spacing. And you can see it here: Microsoft line spacing, aka leading If you look in the Adobe example, you will see that the letters A, B and C mark three different leadings (spaces between baselines of the printed lines)
Whitespace refers to the empty space around objects or text, and can take the form of margins, padding, or just an uncluttered area. It creates a pleasing visual experience and can even draw attention to text. In the first box below, the text is crammed against the bounding box, making it hard to read. In the second box, the text has breathing room and the design even looks more stylish.
Basic typographical terms
Also: Computer language:
In computer programming, white space is any character or series of characters that represent horizontal or vertical space in typography. When rendered, a whitespace character does not correspond to a visible mark, but typically does occupy an area on a page. For example, the common whitespace symbol U+0020 SPACE (HTML ), also ASCII 32, represents a blank space punctuation character in text, used as a word divider in Western scripts.
whites space character
I will not bother with a reference for: write a lead, which is a journalistic term and does not have anything to do with what I explained above. A lead is the first sentence in a news article.