Adobe ACROBAT 3D, Руководство пользователя

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Setting trap thresholds
You can adjust trap thresholds, as recommended by your prepress service provider, to
correspond to your printing conditions. Trap thresholds are available for the following
color conditions:
●
Step indicates the degree to which components (such as CMYK values) of abutting colors
must vary before Acrobat creates a trap. Type a value from 1% to 100%, or use the default
of 10%. For best results, use a value from 8% to 20%. Lower percentages increase
sensitivity to color differences and result in more traps.
●
Black Color indicates the minimum amount of black ink required before the Black trap
width setting is applied. Type a value from 0% to 100%, or use the default of 100%. For
best results, use a value no lower than 70%. (See
Trapping with black and rich black .)
●
Black Density indicates the neutral density value at or above which Acrobat considers an
ink to be black. For example, if you want a dark spot ink to use the Black trap width
setting, enter the neutral density value here. Use any value from .001 to 10, but this value
is typically set near the default of 1.6.
●
Sliding Trap indicates the percentage difference (between the neutral densities of abutting
colors) at which the trap is moved from the darker side of a color edge toward the
centerline, to create a more elegant trap. (See
Using sliding traps .)
●
Trap Color Reduction indicates the degree to which Acrobat uses components from
abutting colors to reduce the trap color. This is useful for preventing certain abutting
colors (such as pastels) from making an unsightly trap that is darker than either color.
Specifying a Trap Color Reduction lower than 100% begins to lighten the color of the
trap; a Trap Color Reduction value of 0% makes a trap whose neutral density is equal to
the neutral density of the darker color.