First poster process thread - sort of successful...

[ShhRecording]

Finally printed my first poster print... I've done some T-shirts in the past, but this is my first flatstock attempt. I've been lurking as a premium member for awhile, studying all the process threads and Gigposter history so I can understand what you guys are saying when you call me a tubdumper. Built myself a vacuum table and, after a few exposure tests and two popped screens (gotta pay attention even when you're washing screens, apparently), whipped up a 3 color design that I could print with one screen (since that's all I have now). Here are some process shots:


Exposing the screen the Ryonet exposure unit I bought a couple years ago when I started printing shirts. Lessons learned: probably shouldn't coat the whole screen if I'm not using the whole screen. probably should have centered the image vertically (which I was planning to do but changed my mind last second for some stupid reason I can't remember). 24 minute exposure. 230 mesh count.


The screen hooked up to the vacuum table. The idea was that I could print one circle, flip it upside down and print the other circle, then print the text, which gets me three colors from one screen. My off contact is maintained by 2 pennies taped to the screen.


First color down: Speedball process Cynine. Didn't print off enough times before loading up the "good" paper so the first few I pulled were a little streaky.


Screen flipped around for the second color... three point registration in place.


Second color: Speedball process Magenta. I didn't really feel like tackling color mixing the first time, plus the straight process colors looked pretty cool, so I just went straight from the jar. This was taken after printing the whole run, so there's not a whole lot of ink left on there, though I gather from other process threads that I'm probably not putting enough on there anyways.


Second color on paper


Pretty sure I stole this trick from someone else's process thread on here, but my lovely wife brought this home from work for me. Makes getting ink on the screen pretty easy and I assume will make color mixing more repeatable, since I can measure quantity fairly accurately. I only have one so far, since the only way she can take them is if they are opened and not used. No longer sterile, but also not filled with Propofol. Taking drugs home from the hospital is usually frowned upon.


Last color down. Speedball black. I could stop the process thread here and make it look like it all went smoothly but that would be a lie. The black nearly killed me. The red and blue went down no sweat (probably because they were just big ass circles) but the black was such a pain that out of the 10 prints I did, only 2 or 3 look any good. Here are some examples of the problem I was having:




Ink would get all over the print side of the screen, I'd clean it off, then print off onto newsprint and it would turn out perfect...

then I'd load up the good paper and it would bleed all over again. It seemed to be worse if I flooded the image, so on the couple that worked out I didn't flood. So I have a big stack of newsprint and unused DBA forms with perfectly printed text and at least 7 or 8 posters with awfully splotchy text. How often do you guys flood with black ink? Seems like with a 230 mesh count, that's probably not the issue... or is it? The only other thing I forgot to do when I printed the black that I did when I printed the other colors was to block the unused holes on the vacuum table... did the paper maybe lift and stick just a tiny bit? It didn't stick to the screen when I lifted it, by I assume it could have been sticking behind the squeegee and then pulling loose when I lifted the screen.

Anyways... I'm hooked, so any help would be most... um... helpful.

--ross

[steve w]

too much off-contact?
too much squeegee angle?
not enough pressure?
did you try not flooding?

and what the hell is so hard about smearing in on a screen with a spatula?
that syringe crap is a waste of time in terms of clean-up.

[Andymac]

that would be the result if the screen was getting sucked down w/vacuum.

[steve w]

also, just coat the whole screen.
that much tape is way more expensive than that much emulsion

[ShhRecording]

too much off-contact?
too much squeegee angle?
not enough pressure?
did you try not flooding?

and what the hell is so hard about smearing in on a screen with a spatula?
that syringe crap is a waste of time in terms of clean-up.

spatula's not hard to use at all, i mostly got it as a way to mix colors that seems like it will be easier for me... plus I tended to make a bigger mess with the spatulas than the syringe when t-shirt printing. And to clean the syringe I just soaked in soapy water for 10 minutes or so and then rinsed it out. No trouble at all.

I did try not flooding and that's how I got the couple of good prints, so I guess that's at least a contributing factor.

that would be the result if the screen was getting sucked down w/vacuum.

How would I address this? Weaker shop vac? Open the hose a bit to lower its power?

also, just coat the whole screen.
that much tape is way more expensive than that much emulsion

Good to know! Thanks.

--ross

[phoondaddy]

Ink too thin?

[steve w]

How would I address this? Weaker shop vac? Open the hose a bit to lower its power?

cover the holes around the paper

[ShhRecording]

Ink too thin?

I wondered about that too, but the ink was straight from the jar. I searched a bit on thickening ink and it seemed like the only methods except evaporating some of the water tend to increase transparency as well... maybe I should leave the jar open for an hour and see.

--ross

[caribou]

i've had that happen with several issues:

wrong squegee angle
thin ink
thin emulsion coat

whenever i see it, it's usually one of these three.

[boatdreams]

I am going to have to second (or third?) the squeegee angle suggestion to combat that bleeding you experienced with the black. When you're back-flooding, you want the handle of the squeegee very close to the screen.
So you put the screen down, pull the ink through the stencil, lift the screen, then lower the angle of the squeegee (handle towards you) to make a very acute angle. Then you push the bead of ink back through the stencil, and you're ready to do another pull.

i've had that happen with several issues:

thin ink
thin emulsion coat

I've found that Speedball black is a little thin right out of the can, too. I usually ad a little bit of brown or violet to it to help thicken it up.
I agree about emulsion. When I switched to a more commercial grade emulsion, I noticed my stencils were way better and I could print much finer details without any bleeding problems.

Nice vac table, by the way!!