Issue Printing top color over underbase

[jwcarder]

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?

[mk162]

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.

[jwcarder]

My underbase is a 150S. For the top color I have tried 230, 155 and 110. Same result no matter the mesh.

[Steve12Lowry]

How is the white underbase printed? 1 layer or a p/f/p?

[jwcarder]

PFP with a roller screen after the first flash.

[Steve12Lowry]

Have you tried just 1 layer of white?

[jwcarder]

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.

[Steve12Lowry]

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?

[zanegun08]

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

[inkman996]

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.

[mk162]

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.

[Homer]

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.

[jwcarder]

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!

[mk162]

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.

[blue moon]

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