File Formats
File formats can affect the amount of time your jobs take to print on a RIP. Telling you which one is best is still determined on an individual job basis. TIFF “Tagged Image File Format" is the most popular image format for photos and scanned graphics. It saves images in a raster format which is basically a dot (pixel) representation. EPS "Encapsulated Postscript" is a highly transportable file format. Since it is already in Postscript, it is easier to process and print. EPS files are "Vector" based. This means that the image is defined by line formulas. The vector formulas allow images to be stretched and rotated without stretching or disfiguring the image. A CT “Continuous Tone” image is the high-resolution image that the printer scans in.

DCS
Are a set of four color-separated EPS images linked to a fifth file that coordinates them. Like EPS, DCS files are highly transportable and contain a low- resolution image for FPO. It can be saved in Binary format which means a faster transfer to the RIP. Since DCS files tend to be larger, the binary format helps to speed up their processing, and save significant time.

Proof Preparation
Make sure all images are defined in CMYK format or PMS (Pantone¨) equivalent. Check that all unused colors in your layout package are deleted from the color palette. Remember, the primaries Cyan, Magenta, Yellow and Black cannot be deleted. If specifying colors from a color matching system like Pantone¨, refer to the printed color swatch book and not the computer screen swatch.

When defining colors of an EPS, define the color with a name. The defined color can then be imported into Quark and PageMaker. Remember to indicate color breakdowns of your design on the accompanying laser proof. Indicate whether they are 'spot', 'process' or combined and note their location on the layout proof. Attach corresponding color chips to the laser proof with their correct identification number. Also remember to indicate the color direction of the vignette and/or blend on the accompanying laser proof. Clearly specify colors selected in the vignette and/or blend and indicate where they begin and end on your accompanying laser proof. An individual proof should be prepared for each page in the finished layout.

Disk Submission
The following items should be checked every time you submit a disk to your printer: Your disk submission should only contain relevant files necessary to produce the job. Check that all text and/or images linked to the layout are on the disk and crop images to the finished size. Do not include any excess image area that should not be reproduced. While checking linked images and/or text files, make sure that their names have not been changed. The layout package's file link utility will help you achieve this. Check your layout file for unused colors and eliminate them. Also check that all color in the layout is defined in CMYK and not RGB.

Revisions
When submitting revisions or Author's Alterations "AA's", we suggest you follow these procedures: Your most recent printer-supplied proof should be marked up with the revisions. A laser proof of the revisions should follow the same checklist procedures you did for your first proof submission. Only submit laser proofs of layout pages that have been changed. Resubmit your computer files using the revision code names suggested in the "FILE MANAGEMENT" section. Modified "LIVE" images are the only exception to this rule. They should maintain the same file name. This will insure the previous links to your file. If a last minute laser proof cannot be submitted with the electronic file, clearly mark the most recent proof with the electronic file changes that you made and include with the electronic file.

Fonts
Fonts are small applications that manage type in a document. Each Postscript font is a precisely matched pair of programs, called the "screen font" and the "printer font." To design a page on the computer, you will need the screen font, and to print the page out to any Postscript device you will need the matching printer font. There is a weakness to the “two-font process” however, the RIP has to search for the corresponding printer font when it is processing a document. To do this, it refers to the fonts name or font ID in the Postscript code. Since font names and ID numbers can change, everyone must be vigilant to avoid this happening. Providing the printer with a suitcase of the fonts used usually solves this problem. Here are some valuable tips about fonts: Use Adobe fonts whenever possible. They are an industry standard, and most printers have them readily available. List all non-Adobe fonts on your Brooks checklist, and indicate their position on the accompanying laser proof. Remember, all font companies are not equally competent. If you use fonts cooked up in someone's garage, expect the RIP not to process them accurately. Fonts are serious software, and most mistakes in a print job are made with fonts. When using non-Adobe fonts, be sure to submit both printer and screen fonts. Screen fonts are just as important, because they allow us to see the layout file correctly. Also, include any customized fonts, even modified Adobe fonts.

Resolution & Rips
Postscript printers, CTP devices and digital proofers all build picture images of a building block called pixels (for "picture elements"). These pixels form a virtual mosaic on a fine grid and form the pictures that we see in proofing and printing. To display an image, the computer makes some of these pixels light and some dark. The finer the pixel grid, the higher the resolution. This resolution is expressed in "dots per inch" (dpi). To process your layout page, every Postscript device has an internal computer processor called a "RIP" or (raster image processor). The higher the resolution of an image, the more pixels it contains and the harder the RIP has to work.

Postscript
The Postscript language is used to move page or layout descriptions form one Postscript device to another. When you print a document, the computer converts what's on your screen into Postscript code in the form of a text file. This standard text file can be out put on any postscript device, (i.e. a laser printer, an image-setter, a digital proofer, lino, and CTP machines).

Image Trapping
Trapping is a way to compensate for misregistration on press, and print professionals use it as a guide to judge quality printing. Image trapping is the intentional overlapping of colors that adjoin each other to prevent the paper stock or substrate from showing through when maintaining tight register on press. Trapping allows press operators with leeway to produce a better quality job across an entire press sheet. Image trapping is different from wet or dry ink trapping which relates to an inks ability to adhere to another wet or dry ink. The ideal time to consider trapping is before and during the design stage. It is best to review your trapping issues with us before your job is submitted to us. We recommended minimum trap for sheetfed printing is 0.25 point or 0.003 inch. Since too much trap can be worse than no trap at all, it is best to allow us to do your trapping for you. Despite the additional cost, it will prevent potential problems once the job is on press, which could be a lot more costly.

Trapping Tips
Trap lighter colors into darker colors Avoid overtrapping Use tinted traps to tone down the appearance of a third color at the border of objects. If colors of nearly equial densities are being trapped, choke the background color into the foreground color. Trap backgrounds into photographic images. Dont trap white knockouts, except in super black situations Don't trap type in small point sizes or with thin serifs, and avoid knocking out this kind of type from multicolor and four-color images. These typefaces, however, are good candidates for overprinting. Overprint hairline rules Watch out for opaque inks. Ink laydown sequence for opaque inks will determine whether an overprint or trap is required. Use common colors among touching objects. Watch out for nested files with inconsistent or incorrect trapping. To trap an object filled with a gradient into a solid object, try to find a color that is present at every level of the gradient and create a trap with that color Trapping is unnecessary on objects that dont touch. ALWAYS REMEMBER, there are occasions when the rules don't work.