[auburn8385]

New to the forum. I have a Javelin automatic press with eight stations. Everytime we print a 4 color process on darks we never get the clarity that we need. I am laying a 15 inch underlay down and then applying the 4 color process on top of the shirt. After printed its not very clear. What can be the causes?

 

[red514]

Hard to tell with little info. if you can provide more info and possibly some pics that would help allot.

 

[auburn8385]

Ok we are printing a shirt it will be on a light blue shirt. We are having to put a underlay that is larger than the image due to the artwork. We have the screens in this order:
White Print Print Flash
Blue 4 color process ink
Red 4 color process ink
yellow 4 color process ink
flashing on the 4th station due to smearing
and then black is going on last
Trying to attach pictures but its not letting me.

 

[red514]

smearing is often due to issues on the press.
what mesh count are you using?
are you using any off contact?
the issue maybe too much ink deposit.
using a sharp squeegee with proper angles helps for a clear print also.

 

[auburn8385]

White screen mesh is 110 the other colors are all on 280 mesh. Wow just looked and our pallets are touching the screen. What is the recommended gap between the pallet and the screen? We have always had problems with the white ink being like sandpaper.

 

[red514]

you want the off contact to be from the screen to substrate, the average is 1/16 up to 1/4 for t-shirts depending on the tension of your mesh.
there's a few threads discussing this and it really depends on your setup and the substrate.

"white ink being like sandpaper'
my first instinct tells me you maybe using a white ink formulated for underbasing but it could be other issues such as the off contact and screen tension. 110 mesh is also fairly coarse, you may benefit from using higher mesh counts for your white, i wouldn't recommend going lower then 200 if you're trying for a clean smooth print.
another cause could be your screens, what emulsion and coating method are you using, 2/1?

 

[auburn8385]

Not sure what you mean "2/1" but we are applying 2 coats of emulsion to each side of the screen. We use Textil Pv emulsion

 

[red514]

Not sure what you mean "2/1" but we are applying 2 coats of emulsion to each side of the screen. We use Textil Pv emulsion

2/1 is referring to 2 coats on one side and 1 on the other. depending on the emulsion. 2 coats on both sides should be ok, that's a thicker stencil tho.
Ink deposit is effected by stencil thickness. I'm not that experienced with coating screens and different emulsions tho.

 

[CNClark]

IF you want better control of printing 4cp on darks, run the job as simprocess instead. Printing straight 4cp on dark shirts is an advanced concept, alot of oldtimers can't do it, and some say it can't be done...it can, but you gotta be good..better yet, you have to know your screens, know your ink, know everything there is to know about squeegee pressures, durometers, EOM, etc. If you are dead set on running 4cp on darks, first thing you need to do is underbase with a 230 mesh, and base out your white ink so that when it is printed it gives a softhanded grey color, flash, then print CMYK, then add a highlite white to keep your white bright. CMYK should be run on 300 mesh screens. In all honesty, if you aren't familiar with off-contact and its importance to screen printing, you have a very tall task ahead of you if you are wanting acceptable results with 4cp on darks. It ain't for newbies.

 

[kla10]

Try printing your 4 color process on a white tee first. That will show you how much of your problem is the underbase vs everything else.(screens, registration, tension, angle, pressure, off contact, etc.) . Also, cmyk is meant to be printed wet on wet. Don't flash between any of the colors or they won't mix properly. It's easier to print process colors on a white tee than any other color, so if you can't get an acceptable cmyk print on a white tee, you're compounding the problems trying to print on a dark tee.

 

[kingscreen]

CMYK process CAN be done on darks but it is quite a challenge. Try printing your underbase with a 200 mesh and your process inks with 305 mesh. The smearing is most likely being caused by too much ink being put down.
[media]http://www.youtube.com/watch?v=gqENVIEolgc[/media]

 

[CNClark]

Try printing your 4 color process on a white tee first. That will show you how much of your problem is the underbase vs everything else.(screens, registration, tension, angle, pressure, off contact, etc.) . Also, cmyk is meant to be printed wet on wet. Don't flash between any of the colors or they won't mix properly. It's easier to print process colors on a white tee than any other color, so if you can't get an acceptable cmyk print on a white tee, you're compounding the problems trying to print on a dark tee.

Excellent advise right here.