in raster engraving, the laser traces a slowly advancing pattern across the surface in a back-and-forth motion like an inkjet printer.
in vector engraving, the line and curve of the pattern to be engraved are followed much like a pen-based plotter draws lines from a pattern outline. early engraving, laser and traditional, of signs and plaques often used prestored font outlines to scale and reproduce letters, numbers, and even logos to size with precise strokes. unfortunately, due to a lack of precision in calculating spacing s, fill areas, as cross-hatching patterns and dot-fills, sometimes showed moir?? effects or uber-patterns. moreover, the font device was not capable of rotations or dynamic scaling. today the postscript software language allows much greater flexibility. just about anything that can be described in vectors by software using postscript, such as corel draw or adobe illustrator, can be outlined, filled in with appropriate patterns, and laser engraved.
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