Ink seeping through screen?

[valkyrie]

Hi Everyone!!!

I'm new here, and moderately new to screen printing, and while i've been watching Catspit's vids on auto-play (because they're awesome), there's a problem I can't seem to find an answer to, and in fact i've never even heard of, happening to a screen I'm trying to print. The ink is seeping through the design in my screen so thickly it's messing everything up (think play-doh press! at least 3mm thick on the print side of the screen!) It's only the side closest to me that's causing a problem.

It's a highly detailed screen with fine line work, on a 156 mesh screen, with white speedball water based ink and a 70A duro squeegee, but the line work seems to be printing fine, it's the larger positive areas that are having seepage. So when I go to print the shirt, either the ink won't go through and I get a faded image, or when I do a second pass, it all smooshes because it collected on the underside of the screen. At first I thought the snap wasn't high enough, so I raised it, and that only seemed to make things worse. And yet, it still looks like it's not snapping properly, as though the off-contact were still too low.

It's not my first time printing, but it's my first time using my new one colour manual press, and it was also my first time coating and burning screens with emulsion. It went way better than expected! Incredible detail! But because of the ink problem, and because it smeared on the underside of the screen, having to wash it out several times to try and correct it, and having to rub it to get the ink to come off, I just saw that my emulsion is washing out!!!! I'm actually quite broken up about it, cause I was so proud of how the screen turned out on the first try after being so nervous about it, but now I have to do it all over again, anyways. The ink wasn't dried in (I would never let that happen to my screen), but it just stuck so much to the emulsion, rubbing and a lot of water spraying was necessary to clean it, and now several cleanings later, pieces of my image are coming off.

Can anyone figure out what I'm doing wrong? Clearly I messed up pretty bad here.

Thanks for any help anyone wants to give me so I can sort this out. I've wanted to see this design printed for over a year now! So close!

-Val

[Shamax]

If I had to guess, I'd look at one of three things:

1) Off-contact. Jonathan says it, and I've made it my mantra: "With off-contact, less is more". 1/16th of an inch should be about the perfect amount of off-contact, and that's what I shoot for when I do shirt prints - and I use water-based inks on a 156 mesh screen as well. When my off-contact was 1/8th of an inch, I had a LOT of problems with the edges of my design getting muddy and blotchy. Setting it down to 1/16" made all the difference in the world. Also, make sure the off-contact is even at all points. Since this is a new manual press for you, check the springiness at multiple points to ensure you've got a fairly consistent off-contact.

2) Are you back-flooding too hard? With water-based inks, of course you have to keep the screen back-flooded to help prevent it drying in he mesh and clogging. But if you press down when you back-flood, you may be smooshing extra ink through that ends-up muddying your design. Make sure you're just lightly brushing it across.

3) Is the ink too thin? If you've never printed with this particular brand of ink, that could also be a culprit. If it's too thin, it might be more prone to seepage.

I'd looks at #1 and #2 first though.

[valkyrie]

Thanks so much for your suggestions, Shamax!

I found a 1/16th thick piece of cardboard, cut it to the size of my platen, loaded a scrap shirt and placed the cardboard over it, and re-calibrated the press so it would sit nicely. I then taped a strip of the same cardboard under the printers' side of the screen to help lift it off the platen. That helped, but not entirely. I'm still getting seepage. I know you're right about my back flooding too hard, but it wouldn't cover the image without working it. It also wasn't shearing nicely when I'd pull a print, leaving a haze of ink on the entire screen. I'd used that very tub of ink before and it worked just fine, grant thou on 80 and 110 mesh screens (and even hand-painting), but it still worked fine.....

...It was then, and only then, that it occurred to me *how long* I had been using that particular tub. No wonder it was thick and hard to manage! *smacks forehead*. So I grabbed a fresh sealed jar of the same stuff and after an ink change cleaning, tried again...

Still no dice.

I should mention that the lower and central part of the image prints just fine most of the time (sometimes after repeated pulls it gets messy) even though that's where the image has the most detail and delicate line work, but the upper part of the image is the problematic part. It's the part with larger positive spaces. However, the worst part, and the only part where the emulsion has started to break down and flake off, are kind of close to the corners of the screen. Not *right* in the corners or anything, but certainly kinda close, due to the image I'm printing. That part has *never once* printed right. Do you think that's where I went wrong? Trying to print too far from the center of the screen?

Turns out, my middle name is Amateur.

Thank you so much for your help!!! It is very much appreciated!

[Catspit Productions]

Okay I’ll chime in here and say Shamax has excellent points made there and I agree with him on that. But now that you have given us further details I would say if you have checked all the above aforementioned items and things are good then you are not such an amateur as you think.

I think you are on to the issue that is causing you problems. With any size screen we have what we call the “sweet spot.” This tends to be the center of the screen because as you get closer to the edges the mesh tension actually changes generally getting higher. If you max out a design on a screen so that it is very close to the frame edge you will have major problems printing that design.

What you’ll need to do in order to print a design that size is move up to a bigger frame size. If you are using a 20x24 inch screen use a 23x31. Or just size the design down to fit inside the screen so there is at least 2 to 3 inches between it and the frame edge. The more the better.

Now on another note as you are using water based inks, you need to make sure your emulsion is water resistant. Then you also need ot make sure it is not under exposed either. If it is under exposed or not water resistant it will absorb the ink and possibly other chemicals if underexposed. That will cause stencil breakdown and possible screen lock.

[valkyrie]

Wow, Thanks Jonathan. If I'm not quite the amateur I think I am it's because i've been working my way through your videos for the past half week since finding them! I think it's really cool that you help all of us out, thank you so much for that. It's very punk rock of you

After some of my own testing, I think you're absolutely right, and I just made a rookie mistake in maxing out my screen area. Live and learn, right? I'm actually using a 16x20 screen, and unfortunately for me, I can't go bigger than that right now (space is a MAJOR issue where I'm working. 20x24 is probably the biggest my press will handle as well. I'll see about picking up some of those but being in canada, shipping is a HUGE issue, and we don't have many good options locally. For the time being I scaled down the design, and I'm keeping my fingers crossed I won't loose detail as a result.

I've reclaimed that screen, printed a new film positive, and the emulsion is drying as I type this. Once it's burned and printed, I'll report back

Concerning the emulsion, mine is rated for water base, discharge and plastisol, so that's not the issue, and I'm not so sure it was underexposed because it washed out perfectly, and then I "baked" it under the lamp. However, I only did so on the print side, and thanks to one of your very cool vids, now I know that the emulsion is softer on the inkwell side, and that's the side it seemed to break down on first, so when I expose this new batch, I'm going to bake on both sides. It might be harder to reclaim, but it looks like I'll have to head to the car wash anyhow, so I might as well (ah, the plight of apartment printing).

Thank you both so much for your help with this, I really appreciate it! And keep those awesome videos coming, Jonathan!

[Catspit Productions]

Sounds good, we all look forward to your follow up post. I appreciate your sharing on the Catspit Forum.

You’re very welcome. I am happy to hear that my videos are helping out and enabling you to learn more about how to screen print tee shirts.

You’re defiantly on the right track with this so I’m sure you should have no problems with stencil and screen size now.

I’ll keep making the videos as long as people keep watching and subscribing the YouTube channel.

And using the Catspit promo codes helps keep things going as well.

http://www.catspitproductionsllc.com/sc ... plies.html

Every little bit of support in any way helps me keep producing videos. The more support I get, the more complex videos I can make. So even a “like” on a video or a sub or just watching the video all the way through from start to finish helps

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

[Rockerstatus]

Hey hey... I'm having the same issue. All of this information has been super helpful! I was hoping to see an update as to how it all worked out. Any news??