On-Screen Font Technology
Who needs high-quality screen fonts?
High-quality screen fonts are recommended for products that rely heavily on text display. CD-ROM publishers, for example, often need clean looking interfaces to enhance and differentiate their product’s appearance. Online documentation and electronic publications are meant to be read. Legible fonts will go a long way in aiding readers within these environments, as well as forms, programs and interactive software.
Why do fonts look jagged on my computer?
Whether you use PostScript or TrueType font technology, the limited resolution of screen displays will degrade the appearance of fonts.
Outline fonts are drawn on the screen by filling in their shape with square pixels. In the Macintosh® environment there are 72 pixels per inch on screen, and in the Windows® environment there are typically 96 pixels per inch on screen. As fonts are scaled bigger or smaller on screen, the size of individual pixels does not change. Therefore, at smaller sizes there are fewer pixels to actually represent the shape of a letter. Diagonal strokes and round shapes need to be simulated by stair-stepping square pixels giving a jagged appearance to these shapes.
The characteristic of jaggedness in low-resolution fonts should not be confused with the jagged look of scaled bitmap fonts. Figure 1 illustrates what occurs when an outline font technology is not being used. If a font size is chosen that does not correspond to an installed bitmap, the nearest size bitmap that is installed is scaled to the requested size. For example, if a 12 point bitmap is scaled to 24 points, the pixels that make up the bitmap are scaled and the font looks very jagged.
Figure 2 illustrates outline font technology in which outlines of letters are scaled to different sizes and resolutions, then filled in with pixels. Shown here is a representation of a 12 point “a” at 72 dpi and a 24 point “a” at 600 dpi. Larger sizes and higher resolutions appear smoother due to the increased number of pixels available to render the shape.
Four fonts at the same point size (150 point) on screen. Note the large difference in the height of their lowercase letters. Larger x-heights tend to give better legibility on screen. Shown from left to right are the Gill Sans®, Dante®, Nimrod® and Andalé® Mono fonts.
What can I do to minimize jagged-looking fonts?
Carefully Choose Fonts and Styles
The design of a font has a great deal to do with how it will render on screen. Certain designs have far too much detail to render cleanly on screen – especially at text sizes. Display and ornamental fonts typically need to be set at 18 point or larger in order to be effective. Monotype Imaging’s typographic experts have worked to create the best possible fonts for screen use and can help you in choosing the right fonts for your application.
Contact us to find out how ESQ fonts can fit into your solution.
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