Any screen printing experts out there?

[Macmann]

We have a phenomenon happening to our gradients on press. Has anyone seen this before? The films we use to shoot the screens are perfectly smooth but we get a ragged look near the midpoint and again in the lighter tones. We have tried multiple dot shapes, angles, resolutions with no luck. Although difficult to capture in a photo my hope was that someone has seen this. The red arrows point to the issue-the green checkmark is just part of the gradient. Any ideas?

 

[Mark]

I would always add noise to the gradient in photoshop to eliminate the banding

 

[Macmann]

Thanks Mark-the film used to create the silkscreen is smooth-no banding to add noise too. I believe this is a press issue.

 

[SteveSuffRIT]

What direction is the squeeze blade moving?
The film looks smooth but how does the washed out screen frame look?
If you rotate the film 90 degrees, not the screen angle, does the pattern direction change?

 

[Macmann]

We set up our tests with the gradient rotated all differently-it didn't matter. Washed out screen looks good as well.

 

[Repro_Pro]

Perhaps the ink is too "long"?
In the sense that it slightly increases dot gain.

 

[mrserge]

Have you tried to change lpi for raster? This is first that comes in mind.