strokes instead of thick outlined glyphs. The advent of desktop publishing brought the need for a common standard to integrate the graphical user interface of the first Macintosh and laser printers. The term to describe the integration technology was WYSIWYG (What You See Is What You Get). This common standard was (and still is) Adobe PostScript. Examples of outline fonts include: PostScript Type 1 and Type 3 fonts, TrueType, OpenType and Compugraphic. The primary advantage of outline fonts is that, unlike bitmap fonts, they are a set of lines and curves instead of pixels; they can be scaled without causing pixellation. Therefore, outline font characters can be scaled to any size and otherwise transformed with more attractive results than bitmap fonts, but require considerably more processing and may yield undesirable rendering, depending on the font, rendering software, and output size. Even so, outline fonts can be transformed into bitmap fonts beforehand if necessary. The converse transformation is considerably harder, since bitmap fonts requires heuristic algorithm to guess and approximate the corresponding curves if the pixels do not make a straight line. Outline fonts have a major problem, in that the Bézier curves used by them cannot be rendered accurately onto a raster display (such as most computer monitors and printers), and their rendering can change shape depending on the desired size and position. Measures such as font hinting have to be used to reduce the visual impact of this problem, which require sophisticated software that is difficult to implement correctly. Many modern desktop computer systems include software to do this, but they use considerably more processing power than bitmap fonts, and there can be minor rendering defects, particularly at small font sizes. Despite this, they are frequently used because people often consider the processing time and defects to be acceptable when compared to the ability to scale fonts freely. Outline font formats Type 1 and Type 3 fonts Type 1 and Type 3 fonts were developed by Adobe for professional digital typesetting. Using PostScript, the glyphs are outline fonts described with cubic Bezier curves. Type 1 fonts were restricted to a subset of the PostScript language, and used Adobe's hinting system, which used to be very expensive. Type 3 allowed unrestricted use of the PostScript language, but didn't include any hint information, which could lead to visible rendering artifacts on low-resolution devices (such as computer screens and dot-matrix printers). TrueType