I have some 22x30's (Cameo or Tempo) from my dealer in Indy, I thought they were too small for you guys or I would have mentioned it. (a month ago) Not for $550, that's a steal.
Yes I own one
Okay people, help me out here.
I'm having a dot gain problem, with a random pattern of uniform small dots. Where the density gets to about 60% they start to grow together and look like splotchy ass. The problem is confined to about the outer sixth of the image, on one side only, where the ink overprints another ink. When I try a print on blank paper, the problem goes away, but returns as soon as I do another on my actual print.
My stencil is great. I have backed off both flood and squeegee pressure, to no effect. Peel and off-contact set as usual and the paper is releasing as it should, no sticking. Ink consistency is the same as always, not runny at all.
This is pissing me off. Particularly because it only happens over another (bone dry) ink. Print looks perfect on a blank test sheet. The only thing I can think of is, the image is placed slightly off center on the screen, with the offending area maybe 3" closer to the frame than on the previous colors. There's still a good 11" of space.
sounds like it is sticking over the other ink. (duh) I've noted this on coated stocks, maybe the other ink is acting like that?. have you covered the exposed vac holes on that side? sometimes the screen gets sucked down just as the squeegee is starting.
squeegee is sharp on that side?
increase the off contact slightly?
increase speed slightly?
can you change your flood to just before the stroke? this risks drying in, but also doesn't allow the ink to ooze through.
Thicken ink slightly?
Switching the flood to immediately before the stroke, was the first thing I tried. Made no difference. I'm pretty confident it isn't the ink seeping through on the flood.
The paper sticking to the screen before the squeegee passes, sounds like that could be it. At least, it's one thing I didn't check for. I didn't have the extra vacuum holes covered, so I'll do that. Usually I do, but I just cleaned out the holes. Squeegee is pretty sharp but I'll flip it around all the same. I don't want to mess with changing the off contact because I superstitiously believe that will mess with the registration, by stretching the mesh more than the previous colors.
Thx Andy, I'll let you know what happens.
yea, more lift will distort or shift, but not a lot. good luck with it. We have been sorting prints today, i just found the Paul Imagine print of somebody slashing their wrist with a squeegee. It's going up in the studio.
I'm curious about mesh tensions, as well as glues, mesh counts. We just ordered a screen stretcher after a lot of trouble getting good tight screens locally. I've always been advised to go with 20-30 newtons, all the screens we have received locally have been trash, in the 12-20 range. Which seems to cause a ton of trouble with our larger screens. We get a wave of mesh ahead of the squeegee creating a nice blurred line at the end of some images, which is no good if its not full bleed.
I was advised recently to start stretching in the 50-60newton range. And some large format graphic printers will even shoot for 70+. Is that really possible? We are stretching 23x31, 30x40, 40x56" screens, ranging from 230-355 mesh. We print UV, waterbased, and solvents.
Another side question, anyone go above 355 for UV printing on bumper stickers? It has never been an option for us ordering pre stretched screens. But we could stretch 380, 420, 460 mesh doing it ourselves... Any big benefit of stocking those mesh counts? I would assume higher quality image, but lower outdoor life? Or are those mesh counts intended for circuit printing and finer details than we would ever need?