What Is the Difference Between CMYK and RGB?

CMYK stands for Cyan, Magenta, Yellow, and Black – the inks a printer mixes together to make colors on printed material.

RGB stands for Red, Green, and Blue – the colors of light a computer screen combine to make colors on screen.

RGB is used for viewing colors on a computer screen, like this website.

CMYK is used for viewing printed material.

Gasch Printing’s presses use cyan, magenta, yellow, and black inks to transform your digital file to printed media. Please ensure your artwork is set up as CMYK. If you use RGB images or colors we will convert these to CMYK for you but the color of your printed file may appear different when printed.

Avoid Rich Black Text
“Rich black” refers to a CMYK ink mixture of solid black over one or more CMYK colors. No registration is absolutely perfect; there is always a little shift or stretch. To eliminate registration issues, make certain all black text is set at 100% black. This ensures your text is only printed once with the black ink.

Solid Black Areas of Color
With digital printing you don’t need as much ink to achieve a good black solid. In fact, if you use too much ink your print will suffer in quality.

For rich black solids, use these values:

    • 30% Cyan
    • 30% Magenta
    • 30% Yellow
    • 100% Black

This provides overall ink coverage of 190%

Using Small Fonts
Be careful when using small font sizes. Gasch does not recommend fonts smaller than 7pt. Remember, the smaller the text the harder it is to keep in register. If you must use small text, we recommend you use 100% black to eliminate any registration problems.

All images should be a required printing standard of 300 dpi (dots per inch). Images should also be placed at 100% size in your final document.

For example, if your image is 2”x 2” at 300 dpi, then it should also be placed in the document at that size and resolution. Lower resolution images compromise quality and may result in pixilation (visible squares or dots that make up the image).

PLEASE NOTE: Opening a 72 dpi image in Photoshop and simply changing the dpi to 300 will not increase the quality of the image.

Borders and Artwork
Because there is always a small degree of movement when printing and finishing a job, Gasch recommends artwork being set at least .25” (1/4 inch) from the edge of the page if it is not meant to bleed off. This is known as the “safe area.”

Avoid printed borders placed too close to the edge of a page as they may look uneven when the job is trimmed.

Please check overprint settings carefully. All overprinting must be correct in a print ready PDF as it is not always obvious to the printer, especially in larger files with many pages.
Use overprint preview in Adobe Acrobat to determine which colors will overprint and which will remain unchanged.

Never set white text to overprint. Setting a color to overprint lays a color over the top of another color. White in CMYK terms is 0%. Overprinting 0% ink on top of another color will cause it to disappear.

It is important that you supply all your artwork with a .125” (1/8 inch) bleed.

Microsoft Word, PowerPoint, and Adobe Photoshop do not offer the ability to add bleed when creating a PDF. You will need to make your page/image size a quarter-inch larger at the beginning. You will then treat the extra .25” (.125 inch all around) as bleed, which will be removed when we trim your job. For example, letter is 8.5” x 11”. Your page with bleed will be 8.75” x 11.25”.

Multiple-page PDF
Do not impose the pages or save them as spreads. This is not print ready. Gasch requires a PDF consisting of single pages running from the first page to the last page. If blank pages are needed in the final book, they should be included in the document. For saddle-stitched books, please remember that the number of pages must be divisible by four (24pp, 32pp, 40pp, etc). For example, if your PDF has 10 pages, you will need to add 2 blank pages before you can print.

The Difference Between Pages and Leaves
A leaf refers to one sheet of paper.

A page is typically one side of that sheet.

So a leaf of paper could be two printed pages (2pp) if double-sided, or just one printed page (1pp) if single-sided.

Raster vs. Vector Text
Rasterized text refers to an image made up of pixels. This typically appears when using Photoshop, a jpeg, or a scan.

Providing rasterized text will result in unclean, “fuzzy” appearance, whereas vector text is made from a clean font or outlines.

Embedding Fonts
Embedding allows fonts used during creation of a document to travel with that document. This ensures that the printer can view and print a document exactly as the author intended.

Force Embedding Fonts
Gasch is able to replace most common fonts with the fonts on our system for an extra cost. However, THIS IS NOT RECOMMENDED.

Force embedding fonts can cause all kinds of issues (spacing between letters, abnormal characters, etc.) The process is not 100% accurate. There may be cases in which the replaced font cannot be detected on a computer screen and can only be seen when it comes off the printer.

Gasch highly recommends a hard copy proof in the event force embedding is required.