Trapping parameters

The Trap Color is determined by selecting the highest value for each ink in the two adjacent colors. Once this value is selected, it is then reduced by the Darker or Lighter reduction value based on its original color (darker or lighter). This new value is now used for the ink in the Trap Color.

The Trapping style can be regular, centered, or special Black. The regular-style trap is done in one direction and spreads into the darker color of the objects' edge. The centered trap is done in both directions. The special Black trap is applied to objects one of which is considered as multi-black and is usually 1.5 times wider than the regular trap if not specified otherwise by the user setting.

The Trap Width depends on the trapping style. Brush width setting controls let the regular trap and special Black width be set in selected units (reasonable values being 0.003-0.006 inches), while the centered trap width is half the size of the regular one.

Density level settings define the amount of ink shared between two colors that must be equal to or greater than the density level in order for a trap condition not to exist. In other words, if the amount of shared ink in both colors exceeds the density level, then there is no trap between these colors.
There are two possible ways of defining Density level: Easy and Advanced.
In an Easy mode only one parameter, SDL (Standard Density Level), is set as the density level for ink with 50% intensity. Other density levels are calculated using the formulae presented in the I-Trap user manual.
In an Advanced mode the user can set either of the density level values for CMYK inks. Values for spot colors will be calculated by the formulae in the specification.
The density issues are discussed in greater detail in the user manual.

No Trap Level setting defines the amount of ink that can be considered as white for the purposes of trap condition calculation.

Dark and Light Ink Percentages are settings used to apply color reduction during the calculation of the trap color, explained above.

Black Special Case rules are applied to multi-black colors or spot colors that can be treated as black if desired. This rule implies that trap direction is always into the black object as it should define the visual edge of the color boundary. The rule depends on the definition of solid black ink specified by the black density level and black color limit (black percentage) settings.

Black density indicates the neutral density at or above which the trapping engine considers an ink to be black. If you want to specify a spot ink to be black, its neutral density should be equal or greater than the black density. An ink treated as Black will cause the Black special rule application if the amount of such ink is greater or equal to the value defined by the Black percentage parameter.

Image trapping rules contain a set of parameters that control Internal image trapping, Image-to-LineWork trapping direction, special Black case and special Yellow case. The special image Yellow case is applied when the Yellow percentage is non-zero and the rules are defined in the user manual.

Miter Trapping is an option to create better looking traps at corners of the objects.

Fine elements is an option that works only when Miter Trapping is On. It causes the trap width to adjust to the narrow shapes.

It should be noted that both the miter trapping and fine elements options require longer times for job processing (up to 30% increase for complex pages).

The Traps highlight is a handy option that allows the user to see traps generated by the TaskForce I-Trap ™ plugin in one of RGB pure colors using the I-Trap Viewer tool. In this case, it is recommended to increase the trap brush width. If none is selected, the trap color will be generated.

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