Black ink not laying down clean when bordering another color
I've been having an issue lately (now that I'm doing more multi-colored designs) where I'm seeing sloppy borders to my black ink (top layer) in spots where I've used trapping. It's like the height of the underlying ink is causing distortion around the trapped edges and it doesn't produce a clean border. I'm also seeing moderate ink buildup around the edges of my stencil (print side) in these instances as well.
I'm printing all colors on 110 mesh...and I'm wondering if the combination of thin, black ink and low mesh count is causing this result.
I'm thinking of trying the black layer on 230 mesh to let less ink through...or possibly buying an additive to "thicken" my ink. I've never liked that the black ink is soooo much thinner than the others.
Anybody have any other ideas as to what could be causing this, and what I could do to fix it??
Re: Black ink not laying down clean when bordering another color
Are you flashing the bottom layer before printing the black? In my experience, printing wet on wet can cause that kind of ink spreading when two colors are printed on top of one another.
Re: Black ink not laying down clean when bordering another color
If that is the problem then perhaps using higher mesh for the bottom layers is a better option than higher mesh for the black layer - this would reduce the height of the ridge.
Last edited by moe_szys1ak; July 20th, 2009 at 11:59 AM.
Re: Black ink not laying down clean when bordering another color
Are you using a softer squeegee? If so, you could be pushing more ink through the screen than you need to. Your angle for holding the squeegee should be 70 to 80 degrees. If it's less than that, again, too much ink. If your screens are too loose and not tight, again, too much ink. If your off contact is too high, again, possibly too much ink. Lots of variables, but typically, with 110's you shouldn't be pushing that much ink through.
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Re: Black ink not laying down clean when bordering another color
You might not need to trap. a butt registration might solve your issue. If not lower your trap specs. If your using a 1pt trap go to a .5 trap or even just a hairline.
Re: Black ink not laying down clean when bordering another color
What black are you using that is so thin? Is it from the same company and line as the underbase? If not, I wonder if using the same line would solve your issue?
Re: Black ink not laying down clean when bordering another color
It's only the black ink that causes this to happen...so my deductive reasoning would lead me to believe that it's got to be due to how thin the ink is.
It's International Coatings' 700 series Jet Black. It's so thin incredibly thin...and the fact that my shop is 90+ degrees in the summer may have something to do with it. It's almost like the ink is falling too far through the screen when I flood, and then the print stroke is essentially "sandwiching" the ink between the screen and the shirt rather than laying it on the shirt uniformly. Maybe I could try eliminating the flood stroke as well.
My stroke is sooooooo much better than it was last year at this time (push stroke), and this is really the only occasion I've been having trouble! No one has ever ran in to similar issues??
Re: Black ink not laying down clean when bordering another color
i once had a similar problem on over printed black with a trapped color
I was printing the red, flashing, then applying my black, the black was all "fuzzy" and not a clean crisp line.
Then after doing that several times, I thought... maybe it's still too hot from the flash?
so i took a ziplock bag of ice cubes, printed my red, flashed... then i dragged the bag of ice across the image a little bit and printed my black... came out fine
I have no scientific excuse for this, but it worked for me... give it a try
Re: Black ink not laying down clean when bordering another color
i have had that problem come up and it seemed that my ink would also build up on the screen and create a double image. in one case i switched the colors. printed black then white and the image came out cleaner and crisper. also personally i have the hardest time printing navy ink on anything that requires white printed also. the navy would smear or would bubble up when i dry.
Black ink not laying down clean when bordering another color 
