Double Strike White

This group is for Summa Printers & Plotters. Questions and issues, advice on all things Summa.
Post Reply
jayhawksigns
Posts: 54
Joined: Mon Feb 15, 2010 12:35 pm

Double Strike White

Post by jayhawksigns » Tue Jan 31, 2017 1:44 pm

Didn't know if anyone has some tips for double striking a multi-pass white job so that you can get a good solid color. The issue I am facing is that the pass lines are extremely noticeable. You know you can always see them on any color in the right light, but with this white ribbon the output, in my opinion, is not sellable. It almost looks like there are two lines where there is only one layer of white.

This is a white vector job, contour cut onto 3M intermediate clear vinyl. Designed in Flexi, exported and printed with SCC. "Default" setting, believe 50lpi and ellipse for the dot pattern. Did try changing the lpi to 30 and it looked the same.

Tried turning color offset off on the printer and rather then being able to see the passes overlaid you now have a faint gap between the passes, and I had just ran an linefeed recently as well.

Willing to try almost anything if some has a suggestion.

Thanks.

PhilJohnson
Posts: 23
Joined: Tue Sep 07, 2010 7:44 pm

Re: Double Strike White

Post by PhilJohnson » Tue Jan 31, 2017 8:08 pm

Hello Jayhawk,

Most of the adjustments you made(color offset, dot shape, frequency, etc.) don't affect the visibility of the overlapping portion when printing with spot colors. Some more important considerations would be your overlap(on, half, off) and your density. The first thing I would do is change your overlap from on to half if it isn't already. I would also try reducing the density if it is much higher than 12,500 as the increased heat and pressure can make the overlapping portion more prominent. After changing both settings I would run the recommended linefeed calibration test and give your job another shot.

Also, if you have any of our premium clear material you might also try printing your job on that to see if the overlap prints better on that material. On some of the more inexpensive materials, like Orajet for example, you have to use such a high heat setting to get the resin to transfer that it almost discolors the overlapping section making it more visible.

If you can email me your contact info to philj@summa.us I can email you a tips and tricks guide that discusses how to correct a visible overlap(banding as most refer to it).

Best regards,

Phil Johnson
Summa Inc.

jayhawksigns
Posts: 54
Joined: Mon Feb 15, 2010 12:35 pm

Re: Double Strike White

Post by jayhawksigns » Thu Feb 02, 2017 12:58 pm

It's amazing how hard it is to get a picture of white ink.

Thanks for the response Phil. I re-ran the job with the default SCC settings and changed some things on the DC4sx, density is at 11,900 (which is what its been set to), changed the overlap to off, and the speed to medium. The attached pic looks almost 100% like it has from the very first attempt at printing this job.

https://goo.gl/photos/M9JNzMRAsoiiyy9q7

PhilJohnson
Posts: 23
Joined: Tue Sep 07, 2010 7:44 pm

Re: Double Strike White

Post by PhilJohnson » Thu Feb 02, 2017 5:54 pm

It's definitely difficult to tell what's going on based off the photo, but I do see the faint overlap in the photo. Is double density turned off? Have you tried lowering the density to something like 10,500-11,000? Do you have any of our premium clear material that you could try printing the same job on to see if you have a visible overlap on that material?

Best regards,

Phil Johnson
Summa Inc.

jayhawksigns
Posts: 54
Joined: Mon Feb 15, 2010 12:35 pm

Re: Double Strike White

Post by jayhawksigns » Thu Feb 16, 2017 4:51 pm

I included a link to a scan of the print. I laid the print onto black vinyl to make the issue easier to see. For reference, the horizontal bar on the T is .805” wide. With scanning it and zooming in, there are several issues in the area between the passes. There is a line where all of the white ink from both layers is gone and the black is showing through. And then there is the roughly 1/16” strip where the second layer of ink is splotchy.

On the left side where I stopped the job before it continued, it looks perfect. A couple of flecks are missing from the edge of the second pass, but overall both a completely there.

These are the settings it was printed at, onto 3M 50 Clear.
Density 11900
Print Speed Standard
Double Density Off
Dot Overlap Half
Color Offset Standard

Changing any of these settings has not seemed to have an effect on the output. Did clean the printhead this morning and went ahead and flipped over the cleaning pad. Wonder if there is an issue with the cleaning roller or the printhead itself.

Going to run the demo file and look closely at the area between the passes.

https://drive.google.com/open?id=0B24Gh ... 2JuWjFubHM

Ran a quick test, printed a cyan box with a cyan mask, color appears to be 100% there, there are two darker fine lines but I'm sure those could be worked out. Then printed it again with a white mask instead and the line is there again.

DecalDude
Posts: 3
Joined: Wed Mar 29, 2017 4:56 pm

Re: Double Strike White

Post by DecalDude » Wed Mar 29, 2017 5:08 pm

In color control, in the advanced tab, check color mask, enter 9 in the top two boxes at the bottom. That will drop two layers of white under the print.

Post Reply