Are You Large Format Computer Graphic Literate? These 4 Questions Will Tell You.

Today it seems there is a large format printer on every street corner. HP5000''s, Encad''s, Epson''s for large format printing (larger than 35" wide) are available at your nearest Kinko''s or Office Max. Many people pull a few files off their internet site, drop them into Photo Shop or Illustrator then take their computer file then submit their saved file to a large format printer and think everything will work out just the way they envisioned it. My experience in producing graphics for the trade show business for the past 25 years tells me otherwise.

In this period of time we''ve gone from one off screen printing for large trade show signs, to utilizing the Gerber vinyl cutter to make garage sale type signs to today''s process which uses computer files for designed for various types of RIPs (Raster Image Processor) that print CMYK (cyan, magenta, yellow and black) images on various substrates from paper and vinyl to polycarbonate. Today most large format printing is done using these RIPs and the ink jet high resolution printers.

What are the land mines ahead for most people? Trade show graphics design requires an understanding of graphics computer software. If you can answer the following questions then you may be able to do your own graphic design. (Anwers provided below).

Vector Art - which programs provide it. What does resolution independence mean?

1) File Resolution - How does file resolution limit final print size?

2) Photographic proportioning - How must you scan a 35mm slide to make it fit a 14" x 150" header layout?

3) If you had a 150 pixel by 150 pixel image and we require 100 pixel per inch how big could this be printed?

4)Your image is scanned at 3200 pixels wide x 2400 pixels tall. You need a 15" x 28" graphic. Is the file appropriate?

If you can''t answer these questions off hand, you need to pay someone to create your graphic art. I frequently have customers submit files who couldn''t answer the above questions and we end up having to recreate their artwork.

Answers:

1. Vector art is artwork created in a drawing program such as Adobe Illustrator. All images must have outlines around them in order to be vectored artwork. These outlines are represented by mathematical formulae that allow the images to be enlarged to virtually any size and still be printed at a high resolution. That is what resolution independence is the ability to scale a graphic to various sizes and still retain high image quality. Scanned images and digital photography (bitmap images consisting of pixels) are not resolution independent, depending on the output device they can only be printed to a certain size and no larger.

2. File resolution limits final print size for all bitmap images (digital photography and scanned images). If you print RIP requires 100 pixels per inch then the final print size of a file 2569 pixel x 3678 pixels is 2569/100 x 3678/100 or 25.69" x 36.78" and not larger unless you are prepared to live with pixelated and otherwise degraded final images.

3. To use a 35mm slide you would have to severely crop the image and scan it at a very high resolution 1400 pixels x 15000 pixels. The example slide at right show a red box that is the proportion of the 14x150 inch header. As you can see most of the image area of the slide is going to be unavailable for the header proportions. That red rectangle representing about 15% of the total slide would have to be scanned at 1400 pixels x 15000 pixels in order to be printed at an acceptable resolution.

4. A 150 pixel x 150 pixel image could only be printed 1.5" x 1.5". Not nearly large enough for trade show graphics usage.

I suggest that if you don''t understand those questions and answers above that you pay someone to do your computer layout for you. You''ll save time in the long run and perhaps even make your deadline.

Bob Albright has been designing and selling trade show graphics since 1982. He is the primary owner of Midland Displays, and you can get further information about trade show exhibits at his website.