Author Topic: Your go to emulsion for halftone work  (Read 9201 times)

Offline balloonguy

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Re: Your go to emulsion for halftone work
« Reply #15 on: October 17, 2013, 08:04:15 AM »
I am very happy with ulano proclaim clear. I do not use those ultra low percentages though. I am also still using a BL exposure. I do know that proclaim does have hr (high resolution). I have loved working with them.
Here is what we can do with a mid quality (2MB) emailed photo printed with solvent based ink through 305 exposed with BL. It is a 50 line screen.
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Offline ABuffington

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Re: Your go to emulsion for halftone work
« Reply #16 on: January 21, 2014, 02:59:34 PM »
Hello Guys,

Al from Murakami here.  As mentioned, Photocure PRO is my choice in a dual cure emulsion for ultimate details, and when hardened with Murakami MS or A&B hardeners it performs well.  SP-1400 is also a great economical choice with very good resolution as well and a little more durability in the 20,000 plus print runs.  If you are looking for a pure photopolymer try Aquasol TS, it is thinner than Aquasol HV or HVP which also have excellent resolution, Aquasol TS is very durable and likes meshes from 150 on up.  If you need a coarser mesh go with Aquasol HV.  All simulated process printers talk about resolving dots below 4%.  The reality is at this tonal level the thread width  is often larger than the halftone dot, whether it's a 45,55, or 65. While some dots may image in the open areas, those that land on thread do not open up or print at all.  This can create what is called 'vignette moire' which is a mild stripe pattern.  Imagine a circular gradation from 100 percent in the center to a 0% on the outside edge of the circle.  Typically there will be some stripes occurring along the edge of this type of print in halftone values below 4%, or even 7% depending on the coarseness of the mesh.  So to avoid this many RIP's can eliminate all dots below a certain tonal value to prevent vignette moire.  If you coat 1:2 dull edge, drop one of the coats to 1:1 dull, or as mentioned above to a 1:2 sharp.  The EOM for high resolution prints should be in the 5-7% range, for discharge in the 10-12% range.  The reason I mention this is the 5-7% will be able to capture finer halftones than a 10-12% emulsion over mesh.  Running at 0% emulsion over mesh will capture even finer details and halftones but it will create issues in production in the form of pinholes or breakdown in the case of discharge.  The emulsion needs to cover the mesh knuckles with emulsion to withstand squeegee abrasion in production.  Resolving the tonal values is only half the picture.  The sidewalls of the open area in Murakami emulsion form a far sharper print shoulder to prevent dot gain.  This vertical sidewall prints a better formed dot.  Expose the Quality - .
Alan Buffington
Murakami Screen USA  - Technical Support and Sales
www.murakamiscreen.com

Offline alan802

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Re: Your go to emulsion for halftone work
« Reply #17 on: January 21, 2014, 03:36:44 PM »
So to avoid this many RIP's can eliminate all dots below a certain tonal value to prevent vignette moire. 

Does anyone know if Accurip has the ability to do this? Filmmaker?
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Offline 3Deep

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Re: Your go to emulsion for halftone work
« Reply #18 on: January 21, 2014, 04:22:30 PM »
imagemate 521 dual cure all the way for me, a very good emulsion

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Offline Frog

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Re: Your go to emulsion for halftone work
« Reply #19 on: January 21, 2014, 04:28:04 PM »
So to avoid this many RIP's can eliminate all dots below a certain tonal value to prevent vignette moire. 

Does anyone know if Accurip has the ability to do this? Filmmaker?

Looks like a possible post subject for the RIP board
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Offline ebscreen

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Re: Your go to emulsion for halftone work
« Reply #20 on: January 21, 2014, 04:37:13 PM »
Zoo asked awhile back, never saw the answer. I've been wanting this feature for a long time.
We use FilmMaker, but there's so many danged options there I don't know if it's possible or not.

Maybe someday when I get the time I'll sit down and.... never happen.

Offline ZooCity

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Re: Your go to emulsion for halftone work
« Reply #21 on: January 21, 2014, 05:18:58 PM »
Good stuff on that eom, we've been learning how longer run DC doesn't seem to need more eom but different eom, that is it seems like your stencil thickness should be sandwiching the mesh with the mesh more to the middle v. plastisol screens where we want that eom on the substrate side primarily.   Blade abrasion on these longer DC runs has been causing breakdown in the form of delamination essentially.   

You can also control resolution with the emulsion.  Some emulsions simply won't resolve a certain size dot on certain mesh counts.  On higher mesh though we bump into this problem of the fabric wales and shirt selection becomes very important.  Thankfully the jobs we run where I want that 3-4% dot are often on higher end garments with a good print face.  Even if the dot doesn't have a clean "landing zone" to print completely, having some ink get through and then blend with the other colors can still push a good print into being a great one.

But I would greatly prefer control over this in the RIP, some kind of limit feature would really clean up certain jobs.  This can be done to some degree manually in PS but man, what a bunch of work and a headache.  The key for a RIP feature would be an ability to trim off 1-3% dots for example without losing signficant data, seems like a delicate task for a RIP to perform.  It's probably available on all those RIPS we're too cheap to buy!
« Last Edit: January 21, 2014, 05:22:28 PM by ZooCity »

Offline alan802

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Re: Your go to emulsion for halftone work
« Reply #22 on: January 21, 2014, 06:03:38 PM »
I always thought you could control the range of your halftone dot till about a year ago I was bitching to my artist to knock off the ridiculous halftone dots that you could barely even see and we were developing some of the really fine ones and getting the moire where normally we wouldn't have been able to get that type of detail on a 305.  I figured we could either not be so damn good at what we do :) or simply knock off the halftone dot range that was giving us the moire problem, under 5% essentially at 55lpi.
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Offline tonypep

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Re: Your go to emulsion for halftone work
« Reply #23 on: January 22, 2014, 09:13:31 AM »
Some may find that with a 55 dpi image, and with some practice, an almost seamless continuous tone graphic can be replicated on fabric with waterbased ink without having to struggle with all this. Most of the rules that have been drilled into us old farts really don't apply. Beginning with screen tension and EOM.

Offline ScreenPrinter123

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Re: Your go to emulsion for halftone work
« Reply #24 on: January 22, 2014, 01:06:16 PM »
Some may find that with a 55 dpi image, and with some practice, an almost seamless continuous tone graphic can be replicated on fabric with waterbased ink without having to struggle with all this. Most of the rules that have been drilled into us old farts really don't apply. Beginning with screen tension and EOM.

If you can convince your clients to go for the matte over the gloss-ier look...still trying to do some convincing with some clients.

Offline ScreenFoo

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Re: Your go to emulsion for halftone work
« Reply #25 on: January 22, 2014, 01:18:48 PM »
Zoo touched on this, but you can remove a certain percentage threshold of dots in PS before it goes to the rip with a curve--which would seem ideal, since you can then compensate the seps for the info you just threw away if it's possible/required.

You can change your calibration curve to no longer print at a percentage in FM as well.   I'd be amazed if you couldn't in accurip, but with all the other 'undocumented features' that program has, I might end up amazed...

Offline ZooCity

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Re: Your go to emulsion for halftone work
« Reply #26 on: January 22, 2014, 02:05:22 PM »
The only way I know of to achieve this in AR would be to set the linearization curve intentionally too low for the % you didn't want.  The problem here is that the curve goes in 5% units so you'd lose 5% down and everything up from 95%, not optimal and you could easily lose key data from the file.

I've seem FM test outputs and it looks like the linearization curve in that rip has control at 1% increments at either end of the curve so this would probably work fine in FM.

Offline ebscreen

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Re: Your go to emulsion for halftone work
« Reply #27 on: January 22, 2014, 02:12:30 PM »
You can change your calibration curve to no longer print at a percentage in FM as well.

Mind elaborating? I start seeing all the options in FM and run for the hills, afraid to fix it until it breaks.

The way I see it, if we can't  resolve it on screen or print it on press I don't want it on the film.
Because some of those 3% dots will resolve and print but not all of them and that makes me angry.

Offline alan802

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Re: Your go to emulsion for halftone work
« Reply #28 on: January 23, 2014, 11:10:13 AM »
You can change your calibration curve to no longer print at a percentage in FM as well.

Mind elaborating? I start seeing all the options in FM and run for the hills, afraid to fix it until it breaks.

The way I see it, if we can't  resolve it on screen or print it on press I don't want it on the film.
Because some of those 3% dots will resolve and print but not all of them and that makes me angry.

You are not alone.  This is something that has bothered me for a while but because I'm embarrased by my lack of knowledge in the graphic design/output part of screen printing I rarely ever talk about it so others won't know I'm an idiot.  I prefer for people to only think I'm an idiot and never really know for sure.
I would rather be exposed to the inconveniences attending too much liberty than to those attending too small a degree of it -T.J.
Those who expect to reap the blessings of freedom, must, like men, undergo the fatigues of supporting it -T.P.

Offline JBLUE

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Re: Your go to emulsion for halftone work
« Reply #29 on: January 23, 2014, 12:24:32 PM »
You can do the same in Wasatch as well. I have mine set for 3% and under to not print.
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