am going nuts trying to get my home screenprinting to work and i just can't work it out.
speedball 110 mesh, coated with diazo photo emulsion, exposed for 5 minutes under a 1000W halogen lamp, through an acetate transparency from an inkjet printer. i wash the emulsion out and i can see the pattern i've exposed - but when i try to take a print, ink just goes through the whole screen. what am i doing wrong? please please help.
speedball 110 mesh, coated with diazo photo emulsion, exposed for 5 minutes under a 1000W halogen lamp, through an acetate transparency from an inkjet printer. i wash the emulsion out and i can see the pattern i've exposed - but when i try to take a print, ink just goes through the whole screen. what am i doing wrong? please please help.
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Re: what am i doing wrong?!?
Thu, March 29, 2007 - 1:43 PMAre you using the correct negative? Is the positive reversed so that only the item you want printed is left on the screen and the rest is open? Sounds confusing but I'm sure that if you think about it it will make sense. -
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Re: what am i doing wrong?!?
Fri, March 30, 2007 - 12:27 AMi'm using a transparency i created, and it's a positive.
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Re: what am i doing wrong?!?
Mon, April 9, 2007 - 2:03 PMto me it sounds like it's not properly exposed, the only reason i say that is cause you said you can see the image you are trying to print a little in the screen-
maybe the acetate's darks are too thin?
i remember having to double up the acetate a long long time ago, and i think that was why...
but not positive. -
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Re: what am i doing wrong?!?
Sun, April 15, 2007 - 12:14 PMYeah, I've run into that too. I remember doing alot of sharpie touchup on those acetates.
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Re: what am i doing wrong?!?
Thu, April 19, 2007 - 3:09 PMSounds like you need more time. That emulsion isn't getting cooked enough to block the paint going through. -
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Re: what am i doing wrong?!?
Sat, April 21, 2007 - 7:01 AM> Sounds like you need more time. That emulsion isn't getting
> cooked enough to block the paint going through.
I second that. otherwise, the emulsion isnt thick enough in the first place? you might need to quickdry the first coat, and re-apply to get it thick enough. in this case, you will almost definitely need to increase exposure time as well.
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Re: what am i doing wrong?!?
Tue, May 8, 2007 - 9:07 PMEm, most likely you are underexposing your emulsion. The Quartz Halogen has very little UV output and will take a minimum of 6 to 12 minutes to expose even a thin deposit of emulsion.
There are however other issues that you should look at as well...
Did you allow the emulsion to completely dry? Like overnight or at least several hours?
Is the light approximately 18 inches from the screen? If it is 36 inches you would need four times the exposure as the distance to time is squared as you back off.
What sort of ink are you using? It is possible that the ink is causing the emulsion to soften and dissolve. There are waterbase diazo emulsions and solvent based diazo emulsions. You need the correct one for your ink.
You can read more about exposure and such at screenprintinganswers.com on the Internet.
Bill Hood
School of Screenprinting
schoolofscreenprinting.com
