Expert: Amy - 2/19/2010

Question
HI Amy

I am Saras from India. Right now i am working as a QC in AD agency. Actually i am facing a lot of time to check trapping, i mean where is necessary or not. Also facing to check where is tapping or not. So if you will help me, then i will be graetfull to you.

What is kicker black? and what is the relation with trapping?
Why we are using kicker black with trapping?

Answer
Hi Saras.

Kicker black is rich black. Rich black is when you add supporting color(s) to 100% black in areas of solid black that you want to appear deeper or less gray than 100%K alone. There are different mixes - a common one is 63C 52M 51Y 100K. A printer I work with prefers 40C 40M 30Y 99K. Ask your printer what mix they recommend. Do not use rich black on small text.

I cannot tell from your message if you know what trapping is. So here's an explanation. When you have two different colored objects on your design that are touching, they can become separated by a small white gap due to printer misalignment. You use trapping wherever you are worried that those gaps may become visible and ruin your design. Trapping is when you enlarge one of those object's borders very slightly to reduce the chance that this physical misalignment will show any white space. Choke and spread are the techniques that are used in trapping. Spread is when an object overlaps the background, choke is when the background overlaps the object.

Most often, trapping is taken care of at the printer, by the software they use. Did your printer tell you that you need to supply your art with trap? Did they specify the size trap they want? For example, .15 pt?

Trapping is actually discussed very well in the Illustrator help file, along with directions on how to trap manually. Have you consulted the Illustrator HELP file? To create a basic trap with Illustrator, select your objects and Choose Window > Pathfinder and then choose Trap from the menu in the top right corner of the Pathfinder window. Specify the thickness of the trap (like .15pt) and click okay.

I can't tell you exactly where or if you need manual trapping in your document or the relationship of rich black in your design to trapping unless I can see your artwork. Do you trap rich black? Yes, you do. You generally spread the K only or choke the CMY, so that only the black itself overlies the edge of the object.

If you need advice for a specific piece of artwork, let me know!
-Amy