Printing other colors after yellow on an underbase

[jvanick]

We ran a job yesterday that had a white underbase, followed by a blue, green, then yellow layer, and finally black.

it was going on dark heather shirts. 

I suppose I could have done the white, flash, black, flash, then the colors and end with yellow, but I was trying to get away with not flashing a 2nd time... (There was a bunch of black in the print which is why I put it last..)

the issue was the yellow was 'smearing' on the black screen, and then would 'smush' out... we were having to stop about every 3 or 4 shirts to wipe the bottom of the black screen.

I've actually never seen that happen like this before... squeegee pressure was just enough to get the black to fully clear the screen. we got through the job, but what a pita.

Thoughts/suggestions to prevent this from happening next time?

I'll get some pics tomorrow...

[Dottonedan]

Spot vector art or sim process?


I typically put Yellow down after white.


(e.g.)
Base white
Yellow
Green
Orange
Red
Blue
Purple
Black
Top white


In Sim, a yellow screen usually has a lot of content. Combine that with a mesh that might have low tension, you then have the yellow sticking to the back of the next screen (if printing wet on wet).


Sounds like it could be low tension on the black screen.

[jvanick]

Spot vector art.  I'll have to check the tension on the black screen.  I know the yellow and other screens are 23 to 26 n

[3Deep]

I know I'm not as skilled as some of the cats on here, but here is what I believe is your problem, your white underbase may be standing up a little and printing all your other top colors only adds to this, about time you get to your black plate it has to print directly on the shirt which you need more print pressure to get a nice coverage causing that yellow ink to blend.  I've had problems like this and it was just about always my white base was a little to high after a flash, I would go to a higher mesh count for my white base or after I've run all my colors flash before I printed the black plate.  I've found out over the years many white inks have a little puff in them even when they say they don't, I now try to find white inks that will lay as flat as possible with a P/F/P.  Printing a high light white will solve this but you'll need a bigger press and a second flash or adjust your black to be printed early if it's to be printed directly on the shirt.  Next time your printing a white base look at how high the ink stands up then print your black plate and check how much print pressure it takes to get a nice cover.

darryl

[Inkworks]

Was the yellow ink a good wet-on-wet ink?

[Homer]

without seeing the art - I may have run black, white, flash - then colors darkest to lightest.....we run colors/black before white often... colors like grey's, black, other darker colors that we never base...things like that.

[jvanick]

The inks are 'supposedly' good for wet on wet work...

Wilflex Epic Quick-White for the base.. applied with a 70/90/70 at almost straight up and down., 156 mesh at 26N, 35psi squeegee pressure.

Other colors Epic PF (finished ink system) on 156 mesh.

None of the inks have any modifiers in them.

200 mesh top black (not sure on screen tension on that one).

Unfortunately the other colors are on V-squegee heads, so I can't really remark much on pressure.  Tried both 70/90/70 and 60/90/60 squeegees on the black and didn't really get much different results.

Picture of the art is attached.  When the black screen is 'fresh'/wiped, the yellow doesn't intrude on the white around the letters (or the green).  When the yellow builds up on the black, it gets freaky.

off contact is just under 3/16"...   (.165")

Pic attached of what's happening.

Edit:  also when the black screen is 'fresh', the screens are in perfect registration.  The out of registration look happens after the ink builds up.

[Prosperi-Tees]

I would run the black and the other colors on 230s and try to run that yellow last on a 156

[Inkworks]

Yup, run the yellow later, maybe a higher mesh, maybe a flash right after it.

Double stroking any top colors? You should be able to get away with single strokes for tops as it will really cut down on gain from getting stepped on repeatedly.

[jvanick]

No double stroking on that.  The yellow takes so long to flash that the triblend shirts this print were on would have scorched

Next time I'll try putting the yellow last.

[mimosatexas]

definitely try higher mesh counts.  I have basically started using 225S or 230 minimum unless it is a one color p/f/p.  For a lot of stuff I have been doing 225S halftoned base with 280 top colors.  This is all manual though and on statics so it probably doesnt apply, but I know I have had much less pickup with the higher mesh.

[Underbase37]

Mmmm, triblends.....be careful putting that black before the flash.

Definitely on that one I would go yellow last or another flash before black. But you know yellow & how well it likes to flash. 

[blue moon]

WOW needs to be printed through thin stencil. You can not use 160 if you are going to step on it. There is too much ink on the underbase and it can not be driven into the shirt as the ubase is preventing that. So what happens is, the yellow deposit, which is tall due to the thick stencil, is now squished and it mushrooms out.

pierre

[jvanick]

Thanks guys!

I'm so used to printing sim process these days sometimes I forget the basics.

Those that are doing a halftone base... what kind of halftone percentages and lpi are you running?  Are you using it as a 'shading' base to add some dimension into the top color?  Or is it just to make a more consistent/thinner topcoat?

any issues with getting the top colors to 'fill-in' the halftone dots?

[Parker 1]

Way to much ink going down.  Bump the base up to a 195-230 mesh and all top colors on 230 with a thinner stencil, like Pier said.

Chris