Raster effect on Go print


#1

Sometimes when I apply the Go overprint, I’ve got a kind of a raster look over a part the print.
You see very fine points with the same distance from each other.

Any suggestion what can cause this?
I’m using QTR for PC on a 2880 printer.

Thanks already!

Best regards
Peter


#2

Hi Peter~

Hmmmm… I have never heard anything like this, so some photos would be very helpful to better understand what you’re explaining, in oder to help you resolve this issue.
When printing GO, what speed and resolution are you selecting in the QTR window? Is the raster looking pattern in the ink image, or GO overcoat?

Best regards~ Dana :slight_smile:


#3

Hi Dana,
Thanks for your quick answer!

It’s happening in the Go overprint. I print on 1440, unidirectional.

It’s not always happening but I noticed something: when I select my Go image(small 4cm square 255,255,255 image) and want to print on an A4 paper size(210x297mm), it mostly looks like a small square white in the preview.
When I see this small image in the A4 preview, the Go will printed ok.
But, sometimes, the Go file looks much bigger in the preview and when I print then, the problem occures.

It seems in the print that the Go print missed some dots on a very regular base, I can try to make a decent picture or scan later and upload it.

Thanks already!

Best regards
Peter


#4

Thanks for the additional information Peter. This certainly is strange, and it would be very helpful for me to either see photos or actual prints to see and better understand what you’re experiencing.
Have you printed a nozzle check on a piece of scrap glossy paper to verify all the GO nozzles are printing before printing the GO layer over an image? GO can only be seen on glossy paper, so in order to see if all the GO nozzles are printing, the nozzle check must be printed on glossy paper.

[B][U]This is how I print GO:[/U][/B]
Print an image with the K7-glossy curve specific to the printer model and paper at 2880dpi and uni-directional speed, then dry the print either for a few hours air-drying or a few minutes of low blow drying. Make a small (1x1” or smaller is fine) pure white (255, 255, 255) 300ppi image in Photoshop, feed the printed sheet back into the printer and print the white square (100% scale) thru QTR by selecting the GO curve at 1440dpi and bi-directional speed to print an even layer of GO over the entire sheet (GO will print evenly over the maximum printable area, depending on the paper size you select).

Keep me posted and let me know if you have further questions, or there’s anything else I can help you with.
Best regards~ Dana :slight_smile:


#5

Hi Dana,

Thanks for your anwer!
I’ve printed exactly like you described and performed a nozzle check too but on semigloss paper and watched it under a magnifier. I hope I have time later today to make a picture of it.
I redo a nozzle check on glossy paper.
It can be 1 bad nozzle, but there are no lines in the Go only a nice pattern with 1 point(nozzle?) missing.
I’ll keep you informed.

Best regards and thanks!
Peter


#6

Hi Peter~ Keep me posted! A perfect nozzle check will produce the best output and GO finish.

Best regards~ Dana :slight_smile:


#7

Hi Dana,
Thanks for your help.
It was a very busy week here, I hope to perform more tests soon, also on matte paper.

Best regards
Peter


#8

I can certainly relate to being busy!!! Please keep me posted and let me know your results, if you have questions or if there’s anything else I can help you with.

Best regards~ Dana :slight_smile: