FAQ: Quark | PageMaker | Illustrator | CorelDraw | Photoshop
Of course, trapping only comes into play in your design when multiple colors overlap or touch each other. If the adjoining color elements aren't trapped, the results can sabotage your design. Therefore you should "worry" about trapping issues throughout the design process so at deadline time you won't have to. That is not to say you should let trapping issues restrict your creativity.
We know that not everybody likes to deal with the task of trapping and some designers simply don't have the time for this sometimes tedious chore. Therefore we take on the responsibility of electronically trapping everything possible in your files before your job goes to press.
In simple terms, yes. In complex terms, no way. Both applications have very capable trapping features but they are limited. By no means should you assume they will be able to handle every trapping situation in your document. For instance, neither Quark nor PageMaker trap imported objects. They can trap page elements to these objects, but they won't trap the objects themselves or the objects to other objects or page elements.
Trapping is part of our electronic prepress workflow and is included in the cost of printing your job. We do not charge additionally for electronic trapping.
First, learn the fundamentals of trapping techniques. Find out when to spread and when to choke adjoining object colors. Understand why we have to trap objects in the first place.
Second, learn your application(s) commands regarding overprinting strokes and fills or controlling trap preferences.
It's a variable dependent on who's printing your job, what kind of paper it is going on, what kind of press it will run on and so on. Every printer should be able to tell you their preferred trap amount for any particular job set-up. Generally it varies between .15 and .5 points. At Extra! Extra! we believe the Quark default amount of .144 points is too small and prefer a trap amount of .20-.25 points for offset sheetfed jobs.
One trick to proofing traps to a laser printer is to enlarge your printout 200-300% to exaggerate the sizing of the objects in question and view color-separated proofs on a light table. Another similar way is to exaggerate the trapping preferences in your document to a much higher amount such as 2 full points and view these seps over light.
1>Check to make sure the object was trapped at actual size and not at a much larger size and reduced in your layout. If you reduced (or enlarged) your object after importing it into your page layout, you also reduced (or enlarged) the trap amount. A .20 point trap becomes only .005 if your object was placed at 25% of its original size. Likewise, that same .20 point trap becomes a full 1 point trap if the object was imported at 500%.
2>Check your stroke thickness in your trapped object. Because of the way drawing applications work, a stroke is rendered from the center of the vector line extending from either side of the vector. Therefore the resulting trap width outside and inside the object's vector is half of the stroke width. In simple terms, you need to double the width of strokes in your drawing applications for the amount of trap you finally need.