Solving banding issues

General tips and techiques used in various sign/graphic design software. Corel, Flexi etc.
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Muts
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Solving banding issues

Post by Muts » Mon Jan 05, 2009 5:39 pm

Solving banding issues...

with CorelDRAW and Summa's Color Control & Printer Control.

The biggest complaint with Summa’s Thermal Printers
is the excessive banding. I hear it constantly, and almost always it's an inexperienced user and or incompatible vinyl.

Some common causes and a solution.

The submitted print ( from this thread ) yup it’s bad...a bunch of things right off the bat
DUST, DEBRIS, CONTAMINATION & PRINT PASS ALIGNMENT. You also notice different
shades or "shifts" in color on each pass of the print head - we will correct 90% this with a linefeed calibration.

Image

Image

Image

Let’s calibrate the linefeed - at the printers console
“Printer Menu” > “Calibrate Linefeed” > Choose 2 “Recommended”

With Clean Media, I print again ” cmy” “default screens”, still slight banding in the
face. ehh

Image

OK lets go back to CorelDRAW, Select your image and go > Bitmaps > Add Noise

Image

I like to sample the real problem area’s, here I choose a medium part of the face.
set level to 50 and density to 50. You probably can get away with less, but time is money.....

Image


I also go into Summa Printer Control and change Colorshift from Standard to HIGH

I then send it to Color Control and leaving the screen freq. alone (55) and change shape to "rhomboid" and print in CMY

The final result......

Image

~Muts

Problem File? Questions? Email me.....

admin@digital-graphica.com

ericopter
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Re: Solving banding issues

Post by ericopter » Fri Jan 30, 2009 3:20 am

http://www.digital-graphica.com/phpBB3/ ... f=10&t=661#" onclick="window.open(this.href);return false;

I'm considering getting a DC4. Is this what I'm in for? When you say incompatible substrate, what do you mean? Is there a list of compatible media other than just the Summa stuff? My local Dealer stocks Avery and Oracal.

I have a regular customer that always needs black stroke on Avery Gold reflective vinyl. Doing this in two color by hand is really not efficient anymore as we are getting busier but not busy enough to bring on more staff hands.

Thoughts?

Cheers
Eric

Muts
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Re: Solving banding issues

Post by Muts » Fri Jan 30, 2009 8:42 am

What is shown above is pretty extreme......

Compatible vinyl list here ~

http://www.digital-graphica.com/phpBB3/ ... p?f=2&t=30" onclick="window.open(this.href);return false;

Some I have used personally, I can't vouch for all of them.
Oracal works well, and so does Avery A9. As far as reflective I have had great results with Nikkalite.
I haven't used any Avery Reflective - straight or printed in a long time..

ericopter
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Joined: Tue Jan 27, 2009 2:35 am

Re: Solving banding issues

Post by ericopter » Sat Jan 31, 2009 3:43 am

I see. What your topic describes is all I keep hearing about the printers. Nice to know that there are great folks who know what's going on.

Great News! and so fast. Will continue my journey.
:)

Ruddbow
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Re: Solving banding issues

Post by Ruddbow » Fri May 27, 2011 9:39 am

TTT

sometimes its great to revisit this post. ALOT of great information.
Summa S75, DC3+ Hobby signmaker.

Vincent
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Location: Belgium

Re: Solving banding issues

Post by Vincent » Fri Feb 08, 2013 8:13 am

Hi there,

Great forum, great topic!

I own a DC4sx since last year May. After some interventions (head allignment, firmware, a new black ribbon, ..) the printer does a great job for photo's en printing in CMY process colors.

My problem, and it's killing me is that in some colors or gradients the color's change in the band or shows a wite line.

The color, for expample, I've a problem with is C:40 M:0 Y:100 (Chartreuse). Even when I drop the LPI to 25 rhomboid it still shows a colorshift, even with 15% noise added to it.

Normally for photo's and full color images larger than 4" I use 25 LPI double dot and works great, even I think for a photo like the tutorial.

What is your experience on this? I can also print on that color of vinyl or a spot color but there has to be a solution to this problem?

Greetings from Belgium.
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Muts
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Re: Solving banding issues

Post by Muts » Fri Feb 08, 2013 9:11 am

that green is what I consider a "dirty color" any tiny shift in material and that's what happens ( the light line is a give away - it's shift/moving ) you could probably get something close using only 2 colors ( yellow & cyan )

Like any other print process there are certain colors I try to avoid.

Temperature and humidity, I run a de - humidifier in the print room and it does
make a difference. Vinyl is very sensitive to temperature

It's precisely why Summa was always pushing their (3m poly liner) vinyl for use in their machines. Summa's printers need a very stable vinyl to get stellar results.

Vincent
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Location: Belgium

Re: Solving banding issues

Post by Vincent » Fri Feb 08, 2013 10:46 am

Hi Muts,

Thanks for the feedback and tips.

Wow, you've experience! I added 5% magenta, a new linefeed cal. en my print is perfect!! Up to 25LPI double dot without banding or colorchange. Picture in attachment.

Your de-humidifier, on how many % humidity is it set on? Last week I had an issue with wrinkling in the magenta ribbon, it was al little off..

We should write our own manual about operating te Summa DC4 :D with pictures and images and under it the settings of the printer for best quality and size. I asked for such examples at Summa but they started laughing.. This because we do it for our job and not always having the time for experimenting en trowing prints away..

What is your advice on gradients. example: red to white.

Many many thanks!
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Muts
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Re: Solving banding issues

Post by Muts » Sat Feb 09, 2013 1:09 pm

Gradients, again simple color... & Gradients should always be close in tone -

Pure hues - C Y M K BLUE, RED, GREEN.

Yellow/Orange
Green/Yellow
Blue/Cyan

etc...

turquoise to pink ain't gonna work...yes I have seen it tried many times here in Jersey...it's awful..


If I was doing red to white I would go with a spot...are you using coreldraw?

My de-humidifier only has knob, it's set in the middle :)

Vincent
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Location: Belgium

Re: Solving banding issues

Post by Vincent » Sun Feb 10, 2013 8:26 am

The file in attachment was my first job, a square with gradient printed in process blue for use with black lettering on a truck. A disaster :( At the end of the day printed in 30 rhomboid I believe.. Eventually it wasn't that bad seen from a distance, no banding :) Since yesterday I learned to print gradients with the 3 colors and the tip from summatech was convert to a bitmap and add some noise but the print quality is not that great then and you still see an overlap in the band. Do you have some examples how you print gradients?

I use Coreldraw (X3) because I'm a vectorman, I got a crashcourse dot's and colors from the dealerguy that installed the printer last year May..

What do you mean with using a spot in red to white?

Do you also know how in Coreldraw or Paint to fade out the edges of a photo into transparency for printing on clear or color? I tried with the transparency tool in coreldraw but no succes, maybe my pc is to slow..
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