Introduction: A Look at the Nuts & Bolts of Preflighting.

The plight of a Designer/Production artist today has become in some ways farely complex with regard to outputting film and color prints. What with a multitude of printers from different manufacturers using different kinds of printing technologies (Inkjet and Laser). These printers utilize different print drivers and very often, specifically if they are not postscript devices, will print differently from one printer to the next. The letter and word spacing and even the graphics may change. This problem is significantly more pronounced when it comes to imaging on high resolution imagesetters that output most film generated for both offset and silkscreen printing. So when a file is transferred to a service bureau for output the results are very often not as expected.

The output facility (Service Bureau/Printer/Magazine) will very often have totally different computers, font configurations and operating system versions (Mac OS or Windows) running. Obviously the potential along the way for problems is pretty high resulting in serious problems and headaches for both parties, with very often no one prepared to take the blame.

Preflighting, is the process of ensuring that all elements needed for the successful imaging of a job are properly in place. This means that all the potential problems that may be encountered have been addressed, corrected and accounted for. The occurrence of problems in this area can be very costly, in time and money, and I’m sure that if you ask most creatives who send their output out, this is a very real problem in the industry today. What can be done about this? We have accumulated what we feel are the most common problems that we face on a daily basis and and have listed them below in the most common order. We recommend that you read these very carefully and develop a preflight routine that you follow consistantly. The time spent will be rewarded manyfold.

1. Missing Fonts
Include all fonts that are used in your publication and any linked graphic files. It is best to include entire font families just in case there is an italic or bold in the document. Send either a TrueType font (1 file) or a Type 1 Screen Font and Type 1 Printer font (2 files). Most programs have utilities that will tell you every font that is used. Some programs such as Illustrator, Freehand, Corel, etc. will allow you to convert type to graphics thereby eliminating the need to send any fonts. This is highly recommended.

2. Missing Linked Files
Send all linked files that are used in your publication. If it’s not there, it won’t print in high resolution. As with fonts, most programs have utilities that will list all the files that need to be included. Some programs, such as Quark Xpress and Pagemaker, have “Collect for output” and “Prepare for Service Bureau” options which will copy everything needed (except fonts) to a disc or folder.

3. Incorrect Embedded Files
Some programs will allow to store a copy of a file or “embed” it in the publication. This usually leads to complications if something turns out to be wrong with a file as it is impossible to modify the embedded file unless it is also supplied with the job. Some programs will not even allow you update an embedded file. Because of all the potential problems that could arise, we recommend that if possible you should always link a file, not embed it and if you have no choice, that you send a file copy of the embedded file with the job.

4. Non-Updated Files
If you don’t use a “Collect for output” option, sometimes the linked files you send may have been modified since they were placed in your layout program. Sometimes you may have different versions of a file on your disc - such as a logo - and the wrong one, or one with a different name is put on the disc. Sometimes when files are compressed or decompressed, their modification date will change. This can lead to disastrous results.

5. Incorrect Spot Colors
I have seen files where the customer has asked for a black and blue separation. When the file was opened, there were all sorts of colors listed including Blue, Dark Blue, PMS 300, Pantone 300 CV, Pantone 300 CVC with a few reds and purples thrown in for good measure. Different programs have different ways of naming colors. When files are being imported into other applications, they will usually bring the colors that they use into your layout program. Make sure that all of these colors have the same name and delete unused colors.

6. RGB & Index Color Graphics & Photos
This is one of the most common problems that I encounter. Most scanners scan photos in RGB; monitors are RGB devices; and the human eyeball “sees color” in RGB. RGB and Inex colors are what is used for graphics on the internet. The only problem is that printing presses use CMYK, so these files have to be converted to CMYK. If a you attempt to separate a RGB file, it will only print on the black plate. Programs will convert files using different algorithms and can alter your colors in undesired ways.

7. No Printouts or Composite Printouts are Supplied
Always send a current, separated proof with your job. It really helps on the output end to see what the file is actually supposed to look like. Also, composite color proofs can be very misleading as to spot colors and RGB files (see tips 5 and 6). It may take you a little longer to print out your own separations, but it can save you time and money down the road.

8. Incorrect Image File Resolution
What are DPI and LPI? Dots or pixels per inch (DPI & PPI) refer to the actual resolution of your graphic. Lines per inch (LPI) refers to the screen value you desire on your negative. For color and grayscale images, start with your desired LPI. If you you’re not sure on your LPI, call whoever is printing the final piece - printer, magazine, newspaper, etc. - they will give you the number that they can work with. This number should be between 35 (silk screeners) and 200 (offset four color printing).

Now comes the easy but possibly tricky part. Just double that number and you get your target DPI. DPI = 2 x LPI! An example: if you want to print your negative at 133 lines per inch, your graphic should be 266 DPI. ( you don’t have to be exact, within 10% will be acceptable and remember higher is better than lower)
Anything less can lead to poor quality or pixellated output. Anything more than three times your line screen can lead to extra run time on your output and will not effect your quality in any manner. Anything over 1200 DPI runs the risk of crashing the whole output system.

Scaling graphics: if you enlarge or reduce a graphic after it is placed in another program, you will need to consider how this enlargement will affect your final DPI. Example: a photo that was saved at 266 DPI and then enlarged 400% in another program is now at 66.5 DPI and will print pixellated at any screen value above 35. Once you get the hang of it, your problems will disappear.

Rotate, flip and scale your scans and graphic images in photoshop or the program used to create them. Try not rotate or scale these images in your page layout program. The ideal job will have all graphics scaled beforehand and placed at 100%

9. Page Setup
Always set up your file to to the actual trim size of the page, so that both the electronic document and the final printed piece are the same size with crop marks in the correct place.

10. Trap? What’s Trap?
Proper trap is probably the most important quality a printer is looking for and the least understood by most beginning designers. Basically it means that where two colors touch on a printed piece, trap is the amount that they overlap. If there is no trap (overlap), white spaces could appear where you don’t want them. Because of the nature of a printing press, it is very difficult to perfectly register two or more more colors over the course of an entire print run. With proper trap, colors can shift a little bit (less than 1/32 of an inch) and not ruin your final printed piece. Unfortunately, it would be impossible for me to explain how to achieve proper trap as every program handles trap in a different and unique manner. Some will even trap automatically (this does not always mean correctly) However, most graphic or page layout programs will devote an entire chapter to this subject.

11. Avoid word processing and low end page layout programs
There are reasons why some layout programs cost $40 and some cost $500+. A lot of them deal with how they handle high end printing. The companies who sell their program for $500 make sure that they will print exactly the same on any postscript printer - whether it is a 300 DPI laserprinter or a 2400 DPI imagesetter. You do get what you pay for. Some programs such as word processor and spreadsheet applications were not designed for high resolution film output and can give very unexpected results when you try them. The only way to save money in this area is to spend the money and buy that “good program” in the first place. You will not regret it in the long run.

12. Clean Up Your Files
Remove extra paths and layers before saving your graphic files. This will keep your file sizes smaller and simplify the printing process. Remove any extraneous type and grahics in the margins of your layout.

13. Graphic File formats
Always save your graphics as either TIFF or EPS format, uncompressed. Jpegs and Gifs are great for the web or viewing on the screen but don't work well in the print production workflow.

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