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screen printing => General Screen Printing => Topic started by: artguy on April 13, 2015, 05:30:19 PM

Title: Any suggestions? Halftones making edge wobbly.
Post by: artguy on April 13, 2015, 05:30:19 PM
Hi there Everybody,
I just came upon a little problem with a film I was printing and was wondering if anyone out there has any suggestions on how to make these edges not wobbly. Change screen angle (without making moire)?...have a trap (yes, but how to cover up wobblies)?...etc?
I appreciate it guys  8). attached is the pic
Thanks,
Adrian

Title: Re: Any suggestions? Halftones making edge wobbly.
Post by: Frog on April 13, 2015, 05:41:20 PM
What I'm seeing is merely the white spaces between the dots meeting up with the white space between the pie slices.
Can you get away with outlining the wedges? Otherwise, I see no way with this size dot to not have this visible.
It's the same problem I have when I have a tiny area on a halftoned full size back that they then also want reduced for the breast.
Same size dots, just a lot fewer of them now filling the shape, and yes, it cam get jaggedy.


Then again, I am far from a dot expert, and in fact, hardly touch my RIP.
Title: Re: Any suggestions? Halftones making edge wobbly.
Post by: JBLUE on April 13, 2015, 05:52:03 PM
What LPI is that? The higher you go the less visible it is. A dot can only simulate so much of a percentage of color.
Title: Re: Any suggestions? Halftones making edge wobbly.
Post by: mimosatexas on April 13, 2015, 05:53:21 PM
You could use the bitmap method to make the angle of the halftones different for each slice where this is an issue, or as frog suggested, outline very lightly.
Title: Re: Any suggestions? Halftones making edge wobbly.
Post by: 3Deep on April 13, 2015, 05:57:54 PM
the only way I see to fix that is to do each slice by itself, instead of trying to halftone the whole circle at once.

darryl
Title: Re: Any suggestions? Halftones making edge wobbly.
Post by: screenxpress on April 13, 2015, 09:27:27 PM
What LPI is that? The higher you go the less visible it is. A dot can only simulate so much of a percentage of color.

Am curious myself.  Looks big, almost like 25 or 30.
Title: Re: Any suggestions? Halftones making edge wobbly.
Post by: jvanick on April 14, 2015, 07:51:29 AM
you could also do your halftones in photoshop in a full circle, and then 'cut' your sections out of the full halftone circle, that way you'd get 'half' a dot or whatever the angle cuts it at.
Title: Re: Any suggestions? Halftones making edge wobbly.
Post by: artguy on April 14, 2015, 12:30:45 PM
Wow thanks guys! I appreciate the suggestions.

This is a 50 lpi, 22.5 degree screen angle, eliptical dot rip (AccuRip) and it's a close up picture. It is about 2" dia. in actual size. Yes there will be a trap in those lines. Actual art is a gradiated orange (white glow in middle) ball with white lines slicing it up into pieces. I thought just putting those traps down would hopefully make the difference, but I don't know if that would be the solution or should I try altering screen angles? just not sure. Maybe I'm overthinking this a bit.
Thanks for all you help,
-Adrian
Title: Re: Any suggestions? Halftones making edge wobbly.
Post by: Frog on April 14, 2015, 12:44:40 PM
Wow thanks guys! I appreciate the suggestions.

This is a 50 lpi, 22.5 degree screen angle, eliptical dot rip (AccuRip) and it's a close up picture. It is about 2" dia. in actual size. Yes there will be a trap in those lines. Actual art is a gradiated orange (white glow in middle) ball with white lines slicing it up into pieces. I thought just putting those traps down would hopefully make the difference, but I don't know if that would be the solution or should I try altering screen angles? just not sure. Maybe I'm overthinking this a bit.
Thanks for all you help,
-Adrian

I think that whatever you do, I believe that given the parameters you spelled out, especially the very small size, you will always have some of those dots or spaces between cut off by the white lines and get this effect.
Title: Re: Any suggestions? Halftones making edge wobbly.
Post by: Squeegie on April 14, 2015, 04:27:24 PM
I would think with a 55 lpi and a 2" size that you may not even notice it when it hits the tee.



Title: Re: Any suggestions? Halftones making edge wobbly.
Post by: Fluid on April 14, 2015, 08:15:21 PM
What is the percentage of color in the art? Try changing that and go to a 55lpi.  As mentioned a lit of that will not be as noticeable once burned and printed.

Richard Reilly - Fluid