About type

Type consists of mathematically defined shapes that describe the letters, numbers, and symbols of a typeface. Many typefaces are available in more than one format, the most common formats being Type 1 (also called PostScript fonts), TrueType, OpenType, and CID (Japanese only).

When you add type to an image, the characters are composed of pixels and have the same resolution as the image file--zooming in on characters shows jagged edges. However, Photoshop and ImageReady preserve the vector-based type outlines and use them when you scale or resize type, save a PDF or EPS file, or print the image to a PostScript printer. As a result, it's possible to produce type with crisp, resolution-independent edges.