Typesetting has some proven rules which are best followed. Many errors derive from applying typewriter habits to word processing or DTP programs. Remember to use an appropriate font for the body of text with a size that makes reading comfortable.
If you are creating a document with long blocks of text, such as a book, or a long article in a magazine, never mix too many different fonts in each page. Restrict yourself to an absolute maximum of 4 different fonts, including the italics. If you can get away with fewer fonts, 2 or 3, even better.
The leading (the spacing between text baselines) is another important characteristic of the text. Many programs have a “double-space” option, reminiscing of the old days of mechanical typewriter. It’s better not to use them. All word processing programs allow to establish an exact value for the leading, be it absolute or relative. See the table of recommended values on the left side; too small or excessively big values make the reading more difficult. The difference between a text badly set (or one with the nasty double spacing) and a text with correct leading is like the night and the day.
Normally, a leading of the 120% to the 140% of the size of the text is perfect. This means that, approximately, for text at 11 points, the space between baselines of two consecutive lines must be between 13 and 15 points. For other sizes, check out the table.
Take care with the text alignment. Full justification alignment isn’t necessarily more professional-looking. Take a look to any printed publication. It will surprise to you to see that, in fact, the alignment to the left is also very commonly used. This is because left alignment is the option that obtains a better distribution of the letters in each line, without blank spaces or altering the letter spacing (adding extra letter spacing or word spacing is usually bad and best avoided, except for titles.) The other options —alignment to the right and centered alignment— must be used exclusively for short texts (captions, titles, summaries...) since they make reading more difficult.
The separation of paragraphs is very important. This is very important, not only aesthetically, but also to avoid problems with the text blocks and text flow. The paragraphs must never be split with two carriage returns. Never! Use always the paragraph options of your application. For example, see this picture which shows the dialog in Word, in Format | Paragraph. Here you specify the indents, separation between paragraphs, how to control consecutive paragraphs... this is a vital part to have professional-looking text and avoid composition problems, like unexpected line breaks and empty lines at the end or beginning of pages.
When you want to mark the beginning of a new paragraph in the text, there are two options, mutually excluding. Use one of these two alternatives, but never both in the same text. Of course, you shouldn’t set the text with neither of the two options.:
- Bleed the first line. The standard typesetting value is of 1 em, a relative unit equivalent to the width of an M letter, and equal to the current size of the font in points. If you work in points, for example, at 11 pt, 1em equals 11 points (approximately three blank spaces.) For normal texts in a book or a magazine with regular paper size, a larger bleed, say more than a centimeter (half an inch) is too big. Again, ’t trust the program’s defaults, usually too large. Specify this first line bleeding in the program options for paragraph, not typing extra spaces or tabs! You can leave the first line with no bleeding, because it’s clear where it begins with no further changes.
- Leave some extra space between paragraphs with no first line bleeding. Again, you have to specify this extra spacing in the paragraph options of the program, never with extra carriage returns..