- Manual Trapping
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- [Part 3 of 6]
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[Part 4 of 6]
Trapping Lines. The trapping techniques above work well for filled paths,but what open paths? After all, you can't apply two different stroke properties to a single path. Instead, you clone the path and make the width of the clone larger or smaller to achieve the spread or choke you want. One of the strokes overprints; the other line knocks out.
Follow these steps to spread an open path (see Color Example 2).
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Draw a rectangle. Create a spot color and fill the rectangle with it.
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Draw a path inside the rectangle.Create another spot color and apply it to the path. Do not set this path to overprint.
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Select the path and clone it.
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Press F10 to display the Stroke palette. Increase the stroke weight of the path by twice the amount of spread you need (remember, PostScript strokes grow out f rom their centers) and check the Overprint Stroke option in the Attributes palette to make the stroke overprint.
That's all there is to it. The original path knocks a hole in the background rectangle, and the clone of the path spreads to just a little bit beyond the edges of the knockout.
To choke the path, follow these steps (see Color Example 2).
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Draw a rectangle. Create a spot color and fill the rectangle with it.
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Draw a path inside the rectangle. Create another spot color and apply it to the line. Set this path to overprint.
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Select the path and clone it.
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Display the Stroke palette. Decrease the weight of the path by twice the amount of choke you need. Leave the Overprint Stroke option in the Attributes palette turned off.
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Use the Direct Selection tool to select the original path. Press Command-Shift-]/Ctrl-Shift-] to bring it to the front.
This time,the cloned path is narrower than the original, and knocks out an area that's slightly smaller than the original path, creating a choke.
Trapping Text. Text is usually the element in a publication that needs trapping the most. For whatever reason, it's easier to notice poor trapping around text than around other elements. At the same time, traps that are too large distort the shapes of the characters you're trapping. It's especially a problem with small type, especially serif type.
Here's how to create a spread for text (see Color Example 3).
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Draw a rectangle,create a spot color ("Color 1"), and apply it to the rectangle.
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Enter text in a text frame. Position the text frame on top of the rectangle so that it 's entirely within the area occupied by the rectangle.
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Create a second spot color ("Color 2") and apply it to the text in the text frame.
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While the text is still selected, display the Stroke palette. Enter the stroke weight you want (remember, it's two times the amount of trap you want) in the Weight field. Turn on the Overprint Stroke option in the Attributes palette.
The next example shows how you can choke text by making the shape the characters knock out of the background a bit smal ler than the characters themselves.
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Draw a rectangle,create a spot color ("Color 1"), and apply it to the rectangle.
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Create a text frame. Position the text frame on top of the rectangle so that it's entirely within the rectangle.
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Create a second spot color ("Color 2"). Select all the text in the text frame and apply "Color 2" to the fill of the text.
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Without deselecting the text, press F10 to display the Stroke palette. Enter the stroke weight you want for the trap in the Weight field. Turn on the Overprint Stroke option in the Attributes palette.
If text crosses color boundaries, use the techniques described earlier for trapping overlapping paths.