Trapping

Trapping refers to how much overprinting colors overlap to eliminate white lines between colors in printing. Trapping digital files are used for compensating for misregristration on the printing press by printing small areas of overlapping color. Dry trapping is printing wet ink over dry ink. Wet trapping is printing wet ink over previously printed ink. The paper or plate applying the ink may shift. It may be 1mm shift but this can throw off your design enough to be noticed depending on the product you are printing. When will you use trapping? When you are printing 2 diffenent colors that overlap they "knockout". They will not print on top of each other. Knockouts may require trapping so there are no color gaps or white spaces where they are not suppose to be on your final product. When using trapping you also need to know how to set the trap depending on the number of overlapping objects, imported images, and the use of gradient fills need to be taken into consideration There is manual trapping in Adobe Illustrator. You can create simple manual traps by applying outlines (overprinting strokes) to objects or use a plug-in that applies the appropriate trap There is also built in trapping in Quark X-Press, Adobe PageMaker and Adobe InDesign If trapping is necessary you can talk to your printer about their recommendations. Printing companies also have dedicated trapping software like TrapWise and Trapper.