Lines in Gradients

[Prism1]

I have a large Grey to Black Gradient ( 12" a 14' ) and it has a bunch of lines "making" the gradient. They are about 1/2" wide, spaced by a couple of inches. How do I smooth these out?? I have tried in both photo and illy with the same results. To make it worse, the "Lines" are a dark, yucky green looking color...

 

[peavey123]

did you try adding some noise to the gradient in photoshop??

 

[Prism1]

I did try adding some noise, it helped a little, but it is still there. This sucks. I have not noticed this before, and did'nt see this one until installing.

 

[Fred Weiss]

There are only 256 colors in the grayscale range if you started at pure white and ended at pure black. Assuming your gradient is running the 14' length, your are displaying those 256 steps of color over a 168" length ... therefore the individual steps will be as you described and will be noticeable if you are standing close enough to it. That's the nature of the beast because it was expected when the standard was created that no one would be standing close enough to a 14' gradient to see the steps. Using noise to even things out can help and increasing the dithering in your RIP may also improve on the results.

The issue of your grays turning greenish is a color management problem. An inkjet uses all four or six colors to create just one color - black in various percentages to approximate the gray. Your challenge is to keep any of those colors from exerting too much influence in every shade of gray you are trying to print. Finding the right profile for your system and the media you are printing is the solution.

 

[Prism1]

Fred...

Yes, the gradient runs the full length. The funny thing is it only happens in certain parts of it. It can be seen standing 6' back. I know the customer will reject it. I have seen this on some banners before, but never a wrap/decal project.

I will try playing with some different profiles on the media. It's Arlon 4560GTX. I am unsure and never played with Dithering in my rip...

Ken

 

[ProWraps™]

good luck getting a smooth gradient at that length. like fred said, each step of the gradient is so large, you will see it no matter what. the fact that its greyscale only serves to ad an enormous PITA on your part. 256 chances to have each step look either green or red. greys suck.