Optimizing print quality
Smooth curves—setflat
PostScript masters that use the PostScript operator setflat produce inconsistent output across different PostScript printers. setflat controls curve rendering smoothness. PostScript curve operators use cubic Bezier control points to define the curve shape. These curves can be rendered from straight line segments. Normally the line segments are so short that the curve appears smooth. The setflat operator indirectly controls the length of the straight line segments. As stated in the PostScript Language Reference Manual, second edition, “If the flatness parameter is large enough to cause visible straight line segments to appear, the result is unpredictable. Setflat sets a graphics state parameter whose effect is
Invisible strokes—0 setlinewidth
PostScript masters that use the PostScript operator setlinewidth are not consistent across different PostScript printers. setlinewidth controls the width of a stroked line. When setlinewidth is executed with an input of zero, it produces a line that is one pixel wide. On devices whose dot size is small, single-
Scan conversion—fill, eofill, and stroke
Scan conversion algorithms are
Sections 2.2 and 6.5 of the PostScript Language Reference Manual, second edition, discuss scan conversion. Section 6.5 states that scan conversion details are not part of the PostScript standard.
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