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screen printing => General Screen Printing => Topic started by: jwcarder on March 23, 2021, 10:15:53 AM

Title: Issue Printing top color over underbase
Post by: jwcarder on March 23, 2021, 10:15:53 AM
I have an issue I have been struggling to solve. When I print royal or purple on top of an under base it is leaving a strange pattern in the top color. I have attached an image. On these, the white didn't fully clear, but it shows the diamond pattern better than my other pictures.

So far I have played with different mesh counts, squeegee pressure and angle, and squeegee euro meter. Then only thing that has word so far is flashing and hitting it with another layer of the top color.

Anyone seen this or have any suggestions?
Title: Re: Issue Printing top color over underbase
Post by: mk162 on March 23, 2021, 10:42:06 AM
What are your mesh counts?  I've found i get that interference if I run the same or similar thread counts on the UB and top colors.
Title: Re: Issue Printing top color over underbase
Post by: jwcarder on March 23, 2021, 11:54:31 AM
My underbase is a 150S. For the top color I have tried 230, 155 and 110. Same result no matter the mesh.
Title: Re: Issue Printing top color over underbase
Post by: Steve12Lowry on March 23, 2021, 12:50:08 PM
How is the white underbase printed? 1 layer or a p/f/p?
Title: Re: Issue Printing top color over underbase
Post by: jwcarder on March 23, 2021, 12:51:15 PM
PFP with a roller screen after the first flash.
Title: Re: Issue Printing top color over underbase
Post by: Steve12Lowry on March 23, 2021, 12:53:01 PM
Have you tried just 1 layer of white?
Title: Re: Issue Printing top color over underbase
Post by: jwcarder on March 23, 2021, 12:54:23 PM
I have and it does work better. Just trying to find a workaround so we don’t have to run a separate hilight white for our smaller runs.
Title: Re: Issue Printing top color over underbase
Post by: Steve12Lowry on March 23, 2021, 01:00:09 PM
Yeah, understood. In that case, you are going to need to lay down much more of the purple ink. Have you tried a softer squeegee at different angles. Very light pressure and faster print strokes?
Title: Re: Issue Printing top color over underbase
Post by: zanegun08 on March 23, 2021, 01:00:19 PM
Why are you basing purple?  It's dark enough on yellow that it doesn't need a base at all.

I don't know the exact reason for that pattern, but we have these same issues with dark purple / greens / blues, I think it is due to the formulas being mostly transparent bases so you don't get a super even distribution of pigment on the print.

This doesn't solve the issue at hand, but drop the base out and it will be no problem.  Also you could try doing a higher opacity mix of the color to help with the opacity of the ink on the base.  Purples I think are the worst offender, then Green, and Reds
Title: Re: Issue Printing top color over underbase
Post by: inkman996 on March 23, 2021, 02:18:13 PM
This is our struggle with royal on top of white UB.We always solve it by going one mesh count lower and usually slowing the print speed down some.
Title: Re: Issue Printing top color over underbase
Post by: mk162 on March 23, 2021, 02:27:07 PM
This is our struggle with royal on top of white UB.We always solve it by going one mesh count lower and usually slowing the print speed down some.

Try one of one stroke's royals.  We have been running the heck out of Comfort Medium Royal and it kills it for us.  Occasionally we will have to hit it with some Visco Minus to get it flowing, but that stuff is money.
Title: Re: Issue Printing top color over underbase
Post by: Homer on March 23, 2021, 02:28:42 PM
This is our struggle with royal on top of white UB.We always solve it by going one mesh count lower and usually slowing the print speed down some.

Try one of one stroke's royals.  We have been running the heck out of Comfort Medium Royal and it kills it for us.  Occasionally we will have to hit it with some Visco Minus to get it flowing, but that stuff is money.

PREACH.... One Stroke is the shizzz... Don't care about the price.
Title: Re: Issue Printing top color over underbase
Post by: jwcarder on March 23, 2021, 02:41:02 PM
I’ll have to look at an ink with higher opacity. I would normally not worry about underbasing a royal in a light color, but for this specific job the customer also had black shirts with the same design.

Thanks for all of the suggestions!
Title: Re: Issue Printing top color over underbase
Post by: mk162 on March 23, 2021, 03:06:22 PM
This is our struggle with royal on top of white UB.We always solve it by going one mesh count lower and usually slowing the print speed down some.

Try one of one stroke's royals.  We have been running the heck out of Comfort Medium Royal and it kills it for us.  Occasionally we will have to hit it with some Visco Minus to get it flowing, but that stuff is money.

PREACH.... One Stroke is the shizzz... Don't care about the price.

Ink cost is such a minute part of what goes into a shirt.  And besides, better ink prints better, less fidgeting on press, higher production all equals more profit.

We have a school here that has a very specific royal and OS medium royal matches it perfectly.  We used to run 2 blues for them, 1 for over a base, and one for direct on a shirt.  Not anymore.
Title: Re: Issue Printing top color over underbase
Post by: blue moon on March 24, 2021, 10:57:21 AM
had to think and look for a second...

that is a moire pattern there. Those are caused by mesh weave and garment weave interfering. I would look at that before anything else.
more ink layers or more opaque ink could solve it, but it's a bandaid. If you don't have a right combo of mesh for that garment weave, bandaids might be your only choice.

pierre
Title: Re: Issue Printing top color over underbase
Post by: 3Deep on March 24, 2021, 11:44:08 AM
had to think and look for a second...

that is a moire pattern there. Those are caused by mesh weave and garment weave interfering. I would look at that before anything else.
more ink layers or more opaque ink could solve it, but it's a bandaid. If you don't have a right combo of mesh for that garment weave, bandaids might be your only choice.

pierre

I was thinking the same as Pierre just didn't know how to but it in words, I've had that problem on some performance wear type garments, did what P said thicker base print help some but still was there somewhat, you might have to adjust your squeegee pressure and maybe a 60 duro
Title: Re: Issue Printing top color over underbase
Post by: Nation03 on March 24, 2021, 04:45:07 PM
180-S usually does the job for troublesome top colors in my experience. 60/90/60 squeegees have been good for better coverage as well.
Title: Re: Issue Printing top color over underbase
Post by: chubsetc on March 25, 2021, 05:17:19 PM
We will run a 50-60% halftone for the base underneath the purple top color (55lpi) on a 150S, 180S if on a smooth T.  We do the same with royals that need based.  If you look close you can see the halftones in the print but from 2 feet away you will never see it.