To remove overprinting:  Select the objects, clear the Overprint Object checkbox on the Trap tab, and then click Apply. Trapping in color separations When objects of different colors touch, there is the potential for an unsightly gap to appear between the colors if the piece isn’t printed precisely aligned, or “in register.” Trapping is a technique that purposely distorts the shapes of objects in color separations where different colors meet. The slight distortion creates tiny areas called “traps” where colors overlap. The trap areas can help avoid the appearance of gaps if the page is printed slightly out of register. Before you use trapping in color separations, you should determine how likely it is that the piece will not be printed in register. You should consider how beneficial it will be to distort the shape of some objects to compensate for possible misregistration. For example, trapping type can ruin the appearance of the text, and probably isn’t necessary. Trapping choices Canvas lets you specify two types of trapping, Choke and Spread. Choke trapping is used to make light background colors trap to dark foreground objects. Canvas creates a choke trap by slightly reducing, (“choking”) the knockout area in the light background object. For example, if a dark blue “A” is printed on a pale yellow back- ground with choke trapping applied to the “A,” the “A” remains exactly the same, but the knockout area in the yellow background becomes a slightly smaller “A” shape. The result is that some of the yellow overlaps the edges of the dark blue “A.” Spread trapping is used to make light foreground objects trap into dark backgrounds. The trap is created by slightly enlarging the fore- ground object without changing the knockout in the background color. For example, if a light circle is printed on a dark background with spread trapping applied to the circle, the circle expands slightly to overlap, or trap into, the circle knockout in the dark background. Trapping limitations Whenever possible, you should design illustrations to avoid certain trapping problems, and always discuss trapping with your service bureau and printer to avoid unnecessary expense and inferior results. Choke trapping reduces the background knockout slightly to trap into a dark foreground object. Spread trapping enlarges the stroke of a foreground object slightly to trap into a dark background object.
Canvas 8 Help: Working with objects (41 of 52)                                                      Page #285