Images printing 1/8" too small

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Why are images printed on my Colorspan System XII-72" exactly 1/8" smaller than the actual size ? If I process an image at 1.o magnification that indicates 29.125" wide, why does it print at exactly 29" ? I've had problems with prints elongating before but the width has never been a prob

-- Anonymous, June 10, 1999

Answers

My guess would be that the synchronizing (or timing) strip on the printer is not exactly 600 dpi and/or the camera reading the strip is faulty. This strip is made of clear rigid plastic with black lines indicating 600 dpi locations for firing the jets as the print head travels back and forth. Every time a black line is detected, the jets that are supposed to fire, should fire in that position with a vertical swath from the printhead. I can guarantee you that we are sending exactly 29.125 inches by 600 dpi = 17,475 pixels in width.

-- Anonymous, July 08, 1999

In September Colorspan started producing accurate encoder strips. If you don't have one get yours replaced...

-- Anonymous, November 09, 1999

This was one of a few reasons I got rid of my Display Maker XII. ColorSpan Found during development that if it mapped its 600 dpi heads to 600 dpi as you would expect that it produced undesirable banding. So they mapped these heads to 601 dpi. This eliminates banding but produces an ever smaller images as your print width increases. Up to 1/4" in my case! I talked to everyone including the president and the final answer was that it was in "spec". My solution was to purchase anouther printer. Print Something exactly 72" wide & measure.Interesting.

-- Anonymous, December 03, 1999

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