RGB vs. CMYK
RGB stands for Red-Green-Blue, which is the name of the color
method used on computer displays. CMYK means Cyan-Magenta-Yellow-blacK.
For images to be printed in color, they must be saved as CMYK. Our press
uses four color plates to produce full color images. If an RGB image is
used in an advertisement, it will print black and white — not color.
Note: Most home color printers will print RGB color. Therefore, it is
important to verify that each image in your ad is CYMK before submitting
your final ad file.
Color Printing
Color Registration refers to the accuracy of lining up the four
colors (CMYK) during the press run.
Ink Coverage refers to how well the ink adheres to the newsprint.
Problems in this area are described as heavy or light inking.
The Gray Bar runs along the bottom of the front page (and sometimes
other full color pages). It's used to help monitor the ink coverage
throughout the entire press run.
Resolution
Vector images are created with mathematical formulas and can be
enlarged or reduced without affecting print quality. Freehand and
Illustrator create vector images. Raster images are created with pixels.
Tiny dots are arranged in grids to create photos and images. Photoshop
can only create raster images, so enlarging or reducing the image can
greatly affect quality.
Gray Scale and Color
Resolution
Should always be 1.5 or 2 times the line screen. The recommended
resolution for photos is 170dpi (or 170 pixels per inch) (85 lines per
inch x 2).
Line Art
Should always be scanned at higher resolutions - usually 600 pixels
per inch. File sizes remain low even though higher resolution is used
because there are no shades of gray or color.
Line Screen
Is the number of dots that are printed from the imagesetter. If you
look at the newspaper under a magnifying glass, you will see that all
text and photos are made up of tiny dots. We use 85 lines per inch.
Dot Gain
Images in the newspaper appear 20-30% darker than proofs or the
image on your screen. The size of the dot enlarges with every step of
the printing process. Newspapers everywhere are working to eliminate
steps in the production process with technology such as pagination and
computer-to-plate. By eliminating these steps, dot gain is reduced,
thereby improving overall quality of the newspaper.
Photocopier Test
If you're not sure if you will encounter a dot gain problem, test
your ad on a photocopier. Make a copy of the ad in regular mode, then
darken the copy 2 notches (20%) with the brightness control. If the
photocopy is too dark, it will print too dark.
Printers' Measurements
- Point: Approx. 1/72 of an inch or 72 points per
inch. Type is always specified in points.
- Pica: Used for linear measurement of type. 12
points = 1 pica, 6 picas = 1 inch.
