Trapping a complex bitmap (exercise)

At the end of this exercise, you should be able to perform the following tasks:

• Process bitmap images as complex bitmaps
• Apply spread or choke traps to complex bitmaps

Note: We recommend that you print this procedure, and follow the steps using the opened drawing file.

1. Open ComplexBitmap.pdf.
2. Start PDF Trap Editor.
3. Click the Trap Page button.
4. In the Images tab, set the Bitmap option to Ignore All. Use the default settings for the other options.
5. Click Trap page.
   A message appears, saying that bitmaps have been ignored.
6. Click OK.
7. Click the object selection tool, and then right-click the blue area just below the red ribbon.
8. Roll the mouse over the menu, and choose Select all complex bitmaps set to knockout.
   This should select the two blue bitmaps.
9. Right-click again in the same place, and choose Select Spread/choke for selected objects. 
   This selects the spread/choke borders for the two bitmaps.
10. In the Properties Editor, click the Trap Direction button once, so that the direction is away from the blue swatch.
11. (Optional) Change the trap size.
12. Click Apply.
13. Zoom into the drop shadow and click to deselect the trap to view it. 
    The blue bitmaps are spread to their backgrounds.
14. To apply a choke trap, reselect the trap by right-clicking the shadow, and rolling the mouse over the menu. Choose Select object's spread/choke.
15. In the Properties Editor, click the trap direction button once so that the arrow points towards the blue swatch, and then click Apply. 
    The background will choke under the bitmap.
    Notice that the entire bitmap must be trapped in the same direction.
    If you want to have the bitmap spread to the dark green background but have the light green choke under the bitmap, retrap the file using the Trap All option in step 3. If you use this option, you sacrifice trapping speed to get the desired result because processing takes several minutes longer.
16. Close ComplexBitmap.pdf without saving.