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Computer and Print Shop Terms You Should Know

At Sundance Printing we never want you to feel stupid. In fact, if it’s any consolation, I had to do a bit of research before I could come up with some of these definitions. It’s really not stupidity, anyway… it’s merely a case of lack of exposure. After all, you have your own business to worry about — probably with lots of words we couldn’t define or even spell very well. But if you are responsible for any printing, then this terminology will help you understand most of what goes on at a print shop. The important part, anyway.

Print Shop Terms

Gripper
The “gripper” is the space at the top of the sheet that is needed for the press to grab the sheet of paper and pull it through the press. The gripper area cannot be printed on. So when your printer is laying out your sheet, they need to consider the non-print area at the top. This only becomes a problem if you are trying to cover the whole sheet with ink. The typical non-print area ranges from 1/4 to 3/8 of an inch.
Halftone
This is the final piece of art your printer needs to print your photograph. Halftones are sometimes referred to as a dot screen — the words are interchangeable. A printer needs to scan the photo and create a bitmap image with photo editing software. This takes your photo, which is a continuous tone (for photography buffs), and makes it into dots so the press can print it.
Line Copy
When a printer says line copy, he or she means the words that are on the sheet of paper you want to print.
Registration
On a properly printed piece, all of the colors are arranged on the page in exactly the same way. If the colors are not arranged properly, the piece will look odd. You’ve seen newspaper photos or advertisements where the colors overlap or are in the wrong place? That’s due to poor registration. Or if you have a line of type with one word in a different color. That one word may be lower or higher than the rest of the line of words because it uses a different plate than the other color. If the two plates are not lined up exactly, then the registration is poor.
 
Line Screen
A line screen is the frequency of the dot screen a printer uses to create halftones from your photos. Newspapers typically print 85 line halftones. Both the metal and polyester plate process typically use 133 line screen for one and/or two color printing. If you are doing four color printing, your printer can go all the way up to a 400 line screen. This much quality is very expensive. Remember, line screen is only referring to more or fewer dots in your photograph.
Color Seperation
Printers need to separate Color 1 from Color 2 because when they print your job, they can only print one color at a time. Let’s say you need to print black and red on your letterhead. Your printer must shoot a plate for the black and another plate for the red. That’s why your printer needs separations. And why registration can become difficult.

Computer Terms

EPS (Encapsulated Postscript)
A file format used for line art or drawings (usually created in Adobe Illustrator, Freehand, Corel Draw or some other drawing program.) These are called vector drawings and are made up of lines and curves.
TIFF (Tagged image file format)
A file format used for scans, especially of photographs. These are best used for pictures that need shades of gray or documents created in paint programs such as Painter or Photoshop. These are also referred to as raster images.
JPEG: (pronounced “j-peg”)
A file format similar to Tiff but using a compression technology that throws out excess color information. These are best used for photographs that will be reproduced as one-color halftones because they take up less disk space than
equivalently sized Tiff files. This is widely used on the world wide web. Images that are downloaded from the internet usually don’t have a high enough resolution to be used in your printing. It will make the image look jagged and detract from the overall attractiveness of your piece
DPI (Dots per inch)
This can be confusing because this term is used for the line screen of a halftone and also for the resolution of a printer or imagesetter. It is better to use the term “lines per inch” (lpi) for halftones. Laser printers generally output at 600, 1200, or 1800 dpi. Imagesetters output at 1200, 2400 or even higher dpi. Halftones are generally printed at 85, 100, 120 or 133 lpi. The higher the lpi of your halftone, the more crisp your document is, but also the morepace it takes up in your file. You’d want really high dpi output from your printer or imagesetter for things like multi-color brochures or pieces with halftones.
BMP (Bitmap)
A low quality (72dpi) file format used primarily for clip art. These are characterized by jagged edges. This is also known as a Pict or Pic on Macintosh computers, and Word meta file on PCs
Pixel
Short for “picture element.” The visual representation of a bit on the screen (white if the bit is 0, black if it’s 1). Also a location in video memory that corresponds to a point on the screen.
 
Color Copier Fiery Unit
This is a Rasterized Image Processor (RIP) which processes a computer image so that it can be output by a color copier, which is the mechanism that allows us at Sundance Printing to send your color copies or your black & white copies directly from the computer to be printed out on the copier instead of placing it on the glass.(See “Color and Black & White Copies”)
 
GIF
Low resolution image used on web pages and not acceptable for the printing process.
PDF
Short for “Portable Document Format.” It’s a file format created by Adobe Systems that allows you to create an image that can be read on any computer anywhere using a special program called Acrobat Reader. A PDF is like a photograph in that it can’t be altered once you get it developed.
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