Author Topic: Overprinting Discharge  (Read 4597 times)

Offline ZooCity

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Overprinting Discharge
« on: August 06, 2012, 05:46:34 PM »
Yet another rookie question from me on this.  We have our first multi-color discharger coming up- Yellow, Black, White, Grey - is how I lined this out.  See attached snapshot of the art.  Going on Asphalt AA 2001, Texcharge for Yellow, Black Grey and CCI D-White for the White.  Print order: Yellow - Grey - Black - White  (sorry I didn't want to post the whole art but yellow is a small area, black largest)

What would you do for combining the white/grey/black to get that third grey tone?

I was thinking just grey (tone adjacent) overprinted by 55lpi black dots but wanted to hear some thoughts. 

Thanks in advance homies. 


Offline 3Deep

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Re: Overprinting Discharge
« Reply #1 on: August 06, 2012, 06:00:50 PM »
You can go about this a few different ways just like you said or go with a halftone black of 35% for the darker gray which will print darker on the shirts after a few prints.

Darryl
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Offline ebscreen

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Re: Overprinting Discharge
« Reply #2 on: August 06, 2012, 07:21:53 PM »
If you went with all waterbase you could either print the dark grey and overlay the white, or
print the (discharge) light grey and overlay with standard wb black. Waterbase is perfect for this kind of stuff,
you would be amazed and the tones achievable. Way better than those halftone things.

Offline jsheridan

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Re: Overprinting Discharge
« Reply #3 on: August 06, 2012, 07:57:27 PM »
over print the black plate in illustrator and print it first.

I did this all the time to simulate a 7th or 8th color on the 6 color press.
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Offline ZooCity

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Re: Overprinting Discharge
« Reply #4 on: August 06, 2012, 09:01:39 PM »
This is why I post here.  You guys always help get the synapses firing.  I agree that using solid overprints is far preferable to halftoning, that's what I love about flatstock printing and I'm excited to bring it into textile prints with dye discharge. 

I'm leaning toward black underneath that dark grey with the light grey on top. 

So: 

Yellow 135/48 - Black 150/48 - Grey 135/48 (overprinting Black for dk grey) - White 135/48 or 110/71 (not overprinting anything)

This way we have one ink to potential mess with on-press, the grey, which is easy, just add a little more black or a little more white and we won't have to "re-charge" it with activator when adding small amounts since it's likely close enough to opaque on it's own in this case, being gray on gray.

What meshes would you run on this compared to mine above?  This is 101 pcs on the manual.  My selections seem a little low and open to me but I want it to print easily and get down in the weave.  Thankfully, the AA Ts with their tighter, ring-spun jersey weave are dreamy to discharge compared to some others we've been through. 


Offline RICK STEFANICK

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Re: Overprinting Discharge
« Reply #5 on: August 06, 2012, 09:46:07 PM »
why not just print a second gray? i must have missed something
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Offline ZooCity

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Re: Overprinting Discharge
« Reply #6 on: August 06, 2012, 10:21:34 PM »
why not just print a second gray? i must have missed something

Saving a color!  Also this looked like a good time to start messing with discharge overprints and taking some notes.  The second, Dark Grey really isn't a critical color, just needs to be lighter than the light grey but not as dark as the black and it will look good.  I want to see how the ink behaves printed this way before utilizing it more. 

I'm a little weird like that and enjoy rolling r&d and production into one thing wherever I can get away with it.  Keeps things interesting.

Offline RICK STEFANICK

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Re: Overprinting Discharge
« Reply #7 on: August 07, 2012, 07:40:31 AM »
sounds like you have the plan 
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Offline ebscreen

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Re: Overprinting Discharge
« Reply #8 on: August 07, 2012, 12:28:00 PM »
180 for what I can see, maybe 230. Only printed WB a few times manually,
but in reality there's not much difference between you and an auto.

Really, seriously, right squeegee/angle/pressure and you can oversaturate fabric
even with 280 mesh.

Offline jsheridan

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Re: Overprinting Discharge
« Reply #9 on: August 07, 2012, 01:33:36 PM »
As far as print order.. darkest to lighest when doing discharge. That yellow should be before the white as its usually a thin color and suffers from pickup when its stepped on.

Mesh count, all 160 unless tones, then 200.
High mesh isn't needed in WB printing like it is for plastisol.
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Offline ZooCity

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Re: Overprinting Discharge
« Reply #10 on: August 07, 2012, 03:05:31 PM »
Got new blade in today- regular ol' 60 duro in a wooden handle and a 14" length of the Manny blade to go in an ergo force handle.  Gettin back on the pull stroke wagon for sure.  Curious about the beveled and grooved manny too.

Thanks John, I'll bump the yellow up to just before the white.

Offline ZooCity

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Re: Overprinting Discharge
« Reply #11 on: August 09, 2012, 03:08:11 PM »
Haven't tested the new blades yet but I'm setting this up like so on Monday:

150  Matsui Black   
150  Sericol White + Matsui Black = Grey 
135  Sericol PMS Yellow 108c 
135  CCI D-White

Still going low on the counts but we don't have a bank of soft and/or bevelled blade in the house right now so we'll need to use 70 duro on at least two of the colors. 

Do you guys have any tips for registering multi-color discharge?  My printer had a hard time doing it on the last one so I suggested printing black first onto a light shirt on this one, flashing it and lining out to that, than pulling the strike offs.  We do use pre-reg which is helpful but still need to make a left to right linear tweak every so many screens.  Reg marks are blocked out with emulsion before going on press for WB jobs.  On all-discharge jobs, I'm guessing you can "very lightly flash" one of the discharge colors until it just appears so you can reg without fumigating your shop with ZFS?

Offline ebscreen

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Re: Overprinting Discharge
« Reply #12 on: August 09, 2012, 03:49:12 PM »
Put reg marks above and below image far enough to be able to stop squeegee from
printing. Print reg color (we never discharge on press, white is opaque enough to work,
or black on light like you suggested) clear tape over test print, reg, wipe ink from reg area,
tape on ink side of screen and try and avoid going over them.


Offline jsheridan

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Re: Overprinting Discharge
« Reply #13 on: August 10, 2012, 09:40:03 PM »
clear tape over test print, reg, wipe ink from reg area,
tape on ink side of screen and try and avoid going over them.

I did that for years and hated it.. it never lines up right due to screen drag.. every screen would be off slightly and I'd have to wipe and wipe and wipe that tape off. took way to much time so I came up with something better..

I've been meaning to make a write up about a "poor mans" registration using default registration marks with out a registration system. Here goes the rough draft, you'll have to imagine it in your head until I make the full write up with pictures and stuff.

Here at the factory I work in now, they use default photoshop/illy reg marks, which means one in each of the four corners spaced just far enough from the image to really get in your way.

I use regular white tape to tape off the inside of the screens and then use clear tape to cover the reg marks using a kind of X pattern. Then flip the screen and use nail polish to block pinholes.

Put the screen in the press and repeat for each color

I have a grid on one of my pallets (3 horizontal lines spaced 1" apart from the top of the pallet and a bunch of vertical lines 1" apart)
With the clear tape, I can see through the screen and use the top reg marks to line up on the 3" down line. This is also the top of my print and is used to locate how far down from the seam the print goes.

Using the vertical lines I center the image with the reg marks as well. I Then place the reg marks so it lines up exactly where a horiz/vert gird line connects. (when the boards get dirty after a bunch of days, I put a piece of white tape on the platten and then draw a new horiz/vert joint with my t-square.

the lines on the pallet, I use a basic ball point pen, are the same size as the reg marks so when the dark line fills the reg lines, it's where I want it. I then line up the rest of the screens to the same location and then add ink and test print.

98% of the time I never have to move a screen from the initial setup. If I do it's a slight tweek here or there and I'm off printing.

Anyone who has used the MHM film locating unit with a reg mark centered top and bottom.. knows exactly what I'm talking about.. this is where I got the idea and ran with it. No more ink in the screens until I' ready for ink. On day like today where the shop was 100 degrees and my discharge ink was kicking in the cups and or drying in the screens waiting for print approval. This method is a life.. no a real Time saver when doing WB work.

« Last Edit: August 10, 2012, 09:50:43 PM by jsheridan »
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Offline RICK STEFANICK

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Re: Overprinting Discharge
« Reply #14 on: August 11, 2012, 11:56:22 AM »
we put 2 registration marks centered top and bottom on every piece of film. the way i line up multi color discharge jobs is print the registration marks in the line up color with plastisol and a little squeegie. flash it and line up the rest of the screens. then just wipe out the little bit of ink and put squeegies /floods and ink in then run a test print. really works well if your doing a set-up at the end of the day intending on printing in the am.
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