Author Topic: Stencil Thickness  (Read 1404 times)

Offline tancehughes

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Stencil Thickness
« on: July 26, 2013, 05:23:44 PM »
Coating 255 mesh, yellow, with chromablue. Getting about 65-70 microns (?) of thickness versus 125-135 on my 110 mesh, white. I would love to bump my 255 mesh up to 90-100 if possible, anyone have any ideas?

Also we are starting to push out more 195 mesh now for our top colors, etc., and would love for those to be in the 100-110 range as well...

Thanks in advance


Offline alan802

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Re: Stencil Thickness
« Reply #1 on: July 29, 2013, 11:07:31 AM »
In my opinion, I think that that thickness for that high of a mesh count would be counter-intuitivepoductive.  On your 110's, is that 125-135 EOM or total stencil thickness?  I've been down this road and 100 micron EOM stencils are fine for some prints and you can really take advantage of stencil thickness playing a role in ink deposit thickness, but for most applications, a 100 micron EOM is wasting a lot of emulsion and will cause additional issues with the print due to the longer "tunnel" the ink has to pass through.

I only say this because there was a time when I thought if 100 micron stencils were working great, then a 150 micron stencil would be even better but it's not the case.  I wanted to challenge most of the gurus when they say to stay in the 15-25% EOM/R for most applications and although there were times that a 200 micron stencil did what I was expecting, for the most part, the thicker stencils did not have the affect I expected and I was wasting emulsion.  I still don't think you want to use a 15% EOM/R for a 110 underbase screen and even 25% is a little weak for me, but I do try to stay in the 30% range and rarely will I go over 40% for screens that I know need to put down some serious ink.  I've printed a lot of things with 50-200% EOM/R and the print would have looked very similar had I just done a 30% EOM/R.

By all means, experiment and try new things, that's what I did.  I'm not trying to tell you to not waste your time with it but rather letting you know what happened while I was doing this very thing a few years back.  I think I got trapped into the thick stencil process when I first tried coating a screen "properly" we went from 0-5% EOM/R to 30% and the results were amazing.  I didn't realize at the time where we were in that relationship between too thin and too thick and I didn't have a tool to measure these types of things in the beginning so I just assumed thicker was better and it certainly is up to a point, but that point turned out to be lower than I had thought.  If we would have had our screens in the 15-20% EOM/R before I started experimenting with stencil thickness, I wouldn't have gotten that false sense of amazement with those first few jobs that were printed with screens that were in the 30-40% EOM/R range.
« Last Edit: July 29, 2013, 11:33:14 AM by alan802 »
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Offline bimmridder

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Re: Stencil Thickness
« Reply #2 on: July 29, 2013, 11:16:18 AM »
Are you sure your numbers are all correct?
« Last Edit: July 29, 2013, 12:06:55 PM by bimmridder »
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Offline ScreenFoo

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Re: Stencil Thickness
« Reply #3 on: July 29, 2013, 11:32:28 AM »
I've always thought EOM was usually expressed as the thickness in microns or the percentage of the mesh thickness, the Emulsion Over the Mesh...