Problems Sizing Prints

[Bohem_gal]

Hey,

My company has recently purchased a mutoh valuejet 2606 and we have encountered problems with printing images to the exact size specified on the rip software and illustrator.
The type of prints we are doing have to be exact and we are finding that a 20ft. print will be off by a couple of inches.
We are creating artworking in illustrator and then bringing it into onyx production house rip and scaling up the image, the final print is almost never exact.

Any suggestions on how to fix this problem

[Jam]

Try working backwards, 20ft scaled down to fit inside illustrator. If your box is a fraction out in illustrator then that may become a couple of inches once you have blown it up. Just an idea.

[PrintDriver]

Printing is NOT an exact science. Certainly not large format printing.
You are going to get creep over 20'. There's no way to avoid it. I usually expect about (+/-) 1/2" to 1" of creep at that size depending on the media and machine.

[Maker]

hey PD, could you explain the reason behind this phenomenon? are aspect ratios skewed when this occurs? do clients ever blow a gasget over an inch off spec at that size??

[budafist]

Is it possible to just work with a huge bleed and hope for the best?

[jimking]

It must be media shrinkage. I know that large web presses have shrinkage. The one I'm familiar with, a 40" nine unit double web, would shrink an 1/8" on each 8.5x11 mag that it produced-- Annoying.

[PrintDriver]

It isn't shrinkage. Most times the image is larger. If you are getting shrinkage, you may be using too much ink (solvents will shrink vinyl and will cause adhesive backed vinyl to fail if there is too much ink)

It is always in the direction of the feed. It can be related to the pinch wheels, the media, or both. Take up reels can help. Or not. It a ll depends on the machine.

My clients don't blow gaskets about an inch over 20'. They know this will happen and usually account for it in their graphic. You don't try to match elements at both ends of a long run. It will not happen.

Where you can have issues is on long seaming runs. This is why you don't let your designers split text. An image or background is far more forgiving at being off a hair than hard text.

[budafist]

It must be media shrinkage.

Is it the cold weather? Must be an embarrassing condition :o

[jimking]

A hot shower cures that! :D

[Drawing a Blank]

<george kastanza>
I was in the pool! I was in the pool!
</george kastanza>

[Booger]

Make sure your roll size setting is correct, or even larger than what is loaded. Sometimes that will skew the size of the image even if you change it or edit in preflight.
Onyx is a great rip (IMO) and I've rarely had problems with sizing unless its some insane corel file thats 800mb before spooling.
PD, go ahead and laugh. :(