What’s Involved In Making The Perfect Stencil?

Here you can discuss issues related to exposing screens for screen printing. This includes determining the exposure, light sources and washing out the stencil in the washout booth. Emulsion issues may also be addressed here.

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Catspit Productions
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What’s Involved In Making The Perfect Stencil?

Post by Catspit Productions »

There are several factors that will determine the quality of your stencil once it is finished on the screen mesh. The first item to consider is the film positive. Make sure the film positive is very dense and has high resolution or print clarity.

The following videos should help out greatly:

http://www.youtube.com/watch?v=JEvWd6D7qCQ

http://www.youtube.com/watch?v=TBdNVbjszmI

http://www.youtube.com/watch?v=KM9uxI2bkPQ

http://www.youtube.com/watch?v=WVhI7xpNkf8

http://www.youtube.com/watch?v=jBmRwap4r6U

The different light sources available to expose your screen will also affect your finished stencil:
http://howtoscreenprintshirts.com/2011/ ... iple-bulb/

Here are some tips on washing out the stencil: http://www.youtube.com/watch?v=tRIFnYUucr0

So what exposure unit do you use? How do you determine your exposure times? What do you use for a washout booth? Do you use a garden hose or pressure washer to washout the stencil? What is your favorite emulsion? What film positives do you find work best?
Jonathan Monaco
Catspit Productions, LLC
Learn how to screen print tee shirts!

http://catspitscreenprintsupply.com/
http://www.youtube.com/user/CatspitProductions
RhinoTech
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Re: What’s Involved In Making The Perfect Stencil?

Post by RhinoTech »

Stencil-making is changing due to new RhinoScreen Dry Stencil Film. The latest video, http://youtu.be/pa0HpQfrj0o, produced in conjunction with Catspit Productions (also on this forum site) details the simplified, step-by-step process that eliminates the use of a film positive, emulsion, capillary film, exposure and drying time. Together with the recommended GO UNO DTS system that is a high performance/high speed tabloid LED Direct-Transfer-Screen printer, a heat press and computer, stencil-making just became east and fast.

Thanks for reading/viewing the video. If you have questions, please contact RhinoTech @ 651-686-5027 ext. 1 or 2 or @ info@rhinotechinc.com.
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ppdlao
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Re: What’s Involved In Making The Perfect Stencil?

Post by ppdlao »

Catspit Productions wrote:So what exposure unit do you use? How do you determine your exposure times? What do you use for a washout booth? Do you use a garden hose or pressure washer to washout the stencil? What is your favorite emulsion? What film positives do you find work best?
Hi Jon, I want to share my exposure "method" if we can call it so! :)

I was just checking out some topics, then reading in this posts I remembered, once I told you I always dry off my screens once coated with a hair dryer, cause I was taught that way (can sound crazy bur works :D ), I can dry one coated screen like in 1:15 min, then I proceed to expose my positive, I´ve never had any problems with it, I just have to be very careful not to keep the hair dryer on the same spot for more than 5 secs, cause the heat can over expose an spoted area of 1 inch aprox and this area do not reveal after exposing, but this is the only problem I´ve had experienced with this "method", and when finishing drying all the screen and if it still has wet spots I turn off the heat of the hairgun and apply just cool air for some seconds, and that´s all. After revealing the screen, I dry it again with the hair gun and then I allow it to dry at room temperature in my backyard but not beneath the direct sunlight, cause mines are wooden made screen frames, and I´m affraid, direct sunlight may cause them to twist, with temperatures around 36°C to 43°C here in the south of México it´s like hell (like your weather in Arizona! 8-) )

I wish I could tell more about my emulsion, but it seems to be called different in the States, I read some info about it from my vendor, and all I could tell about it is, that is not diazo, not dual neither so it has to be photopolymer, it is blue, and I have to mix it with 10% of a photo sensitizer called "BICROMATO" wich is very much like water look but it is yellow, and once mixed the emulsion looks like turquoise, once mixed it lasts 7 days aprox. Just for solvent inks and for Plastisol, if I want to use the stencil for water base inks, once my stencil is detailed and well dryed I have to apply a "hardener" called SERICUR, for "cured" I think, so this hardener is like and smells like alcohol, with a sheet of flannel I apply it all over the screen, both sides, then I "burn" the screen in my Halogen work lights 5mins each side.

I usually do this with one screen at a time, I coat, dry, expose and reveal one by one, doing it like this I should have one stencil ready every 30-35 mins without stopping, and I do it always between 9am and 12pm(mid day) so I close every door and window courtains, I turn off all the lights too, and I expose with 2 Halogen work lights of 500w each one,a table and a glass of 6mm thick like 35cms above the lights. 2:00-2:15 mins for white 158 mesh count and 1:40-2:00 mins for yellow 230 mesh count, the time depends on the weather, when sunny I use the less time, when cloudy I use more time, and wet raining and with "black" sky I use the more mins of the range I just wrote.

Once exposed and dry, I still have to detail the stencils with old emulsion that I have previoulsy stored from the previous week, usually this takes from 15mins to 25mins per stencil. At this point I could never achieve to eliminate pinholes at all or "fish eyes" which are like blank spots that emerge throuhg the coated screen no matter how many times I try to coat it with emulsion, I just did a perfect screen coating like a couple of times I think :roll: I do 3 and 3 emulsion coats per screen side, that´s what works for me so far, I´m still learning :P

I know, my exposure method could sound maybe nasty or rare, but works to me, I don´t have the necessary space neither the professional items needed to improve my method yet and do it like you´ve been teaching us, so the stencil detailing turns very difficult sometimes :oops: I hope soon I could improve my exposure method bit by bit (poco a poco) And I´m about to change my emulsion into Diazo!! beacuse of the waterbase discharge inks I want to use! most of the time printing nice opaque whites over black garments turn my job into a nightmare cause I don´t have a flash cure unit neither a belt dryer, so I found discharge inks like my solution to that, I made some testing last week, and my screens never got clogged! I´ve past the exam! I cured those tees with my heat press, 180°C for 50 secs and the discharge did it well.

So that´s my screen exposure experience for now, as always I hope this could help something or somehow or someone
Thanks for taking the time to read this anyway Jon, sorry for the loooong post :oops:

See you buddy, and thnks for your continued technical support :D
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Catspit Productions
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Re: What’s Involved In Making The Perfect Stencil?

Post by Catspit Productions »

Awesome, I appreciate adding your experience to the forum. I’m sure this post will help people out and it’s interesting to learn about different methodology to screen making.

You’re welcome, it’s my pleasure to help out and share information. :D
Jonathan Monaco
Catspit Productions, LLC
Learn how to screen print tee shirts!

http://catspitscreenprintsupply.com/
http://www.youtube.com/user/CatspitProductions
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