Ed #11 Print It

Bar exam

Printers use color bars and registration marks to help achieve consistent quality and color throughout the project. Registration marks are used to ensure that the different colors are printed in register, or placed on top of one another. Crop marks show where the form should be cut. Fold marks show where and how to fold the sheet. Dot gain scales for each process color show physical dot gain in different increments. Excessive dot gain can cause images to lose detail and colors to shift. Trapping—the bond a wet ink forms with an ink already printed on the paper—can be seen using a loupe on the trapping fields of the color bar. Low levels of trapping can make images and type appear washed out. Screen tint patches, shown for each process color, help assure that screen percentages remain consistent from sheet to sheet. Color can be adjusted across the color bar. A series of lines or concentric circles is used to check for slurring.