Font types: By preference, you should use OpenType fonts. Type 1 or TrueType fonts are also OK but try to avoid Multiple Master or older Type 3 fonts. A lot of systems no longer properly support these fonts.
City fonts: Older Macintoshes come with a series of fonts that are named after cities (e.g. Geneva, Chicago or New York). Avoid using these fonts as older versions of the Mac operating system only supply them as screen fonts which are not suitable for output. This rule does not apply to ‘Memphis’.
Style menu: Don’t use stylized fonts, select the fonts by their long names name. So select ‘Helvetica bold’ as a font instead of selecting ‘Helvetica’ and then clicking on the “bold” style button. Some applications do not show all font faces for TrueType fonts. It that case, you can use the different styles if you are sure the corresponding font exists.
Outline fonts: Try to avoid the underscore or outline fonts from QuarkXPress or other applications. These are gimmicks that can look great on screen but are sometimes impossible to output correctly.
Spelling: Always use the spell checker that is included in most applications to check your document. Add words that appear frequently in your documents to the custom dictionary.
Cross-platform issues: Avoid moving from one platform (e.g. Mac) to another (e.g. PC) because this can cause text to shift slightly. Some fonts that are available on both Mac and PC differ slightly, even if they use the same name.
Colorized text: Don’t colorize small text (e.g. < 8 points) in 2 or more process colors. The slightest registration problem on the press makes such text illegible.
Rectangles, fills and lines
Hairlines: Some applications have a line thickness that is called “hairline”. Never use this, always stick to a specific width, e.g. 0.25 points. The problem with hairlines is that they are imaged as the finest possible line on any given device. This may be fine on a 300 dpi laser printer but a 1 pixel wide line on a 2400 dpi imagesetter is hardly visible. Some workflows allow the operator to set a minimum line width to avoid this trap. Just don’t count on this workaround and avoid hairlines entirely. The smallest line width you can use depends on the press, paper, speed,… Consult your printer. As a general rule, never make a line smaller than 0.2 points.
Total ink coverage: Depending on the paper stock, the type of printing process and the press itself, your printer can specify a certain ‘total ink coverage’ (TIC). This is the maximum amount of ink that any object on a page should contain. For example: if the TOC is 280, you can have objects on the page that contain 70 percent of cyan, magenta, yellow or black but a mixture of 100 percent cyan, 100 percent magenta, 50 percent yellow and 50 percent black has a TOC of 300 which is too much and will lead to smudging on the press.
Solid colors: Avoid large areas of solid black ink which can be very difficult to print. Digital presses tend to have a problem with any large area that contains a solid color.
Colorize thin lines: Don’t colorize thin lines (e.g. < 1/2 point) in 2 or more process colors.
File formats: Avoid file formats like PICT, GIF or BMP which were never meant for design purposes.
Resolution: Make sure images have the correct size and resolution while scanning them. The final resolution of bitmaps should be somewhere between 800 and 1200 dpi. So if you scan a logo and want to enlarge it 300 percent in the layout application, it should be scanned at 2400 to 3600 dpi. For output on digital presses, a resolution of 600 dpi is often sufficient.
Size: Never enlarge images more than 20 percent in your layout application. It will reduce the resolution of the images and lead to an effect called staircasing.