Indigo - Poor Rub Resistance

Signature

Member
While just about any printed piece that is not Aqueous or otherwise coated will rub, but the Indigo seems to be EXTREMELY vulnerable to this and it seems to be it's Achilles Heal. I recently printed a 6 page brochure approx. 4" x 5" finished size. After it was scored and hand-folded, the minimum handling of the finished pieces to jog into a pile of 20 to be rubber banded, scuffed the printed image from the back page onto the front cover of the the piece below, Just thus little bit of handling made the job in my mind unsuitable to deliver to the client. If you cannot get it out of your front door without scuffing, how is the client going receive them. I mean, let's face it, what client wants even the slightest scuffing on the cover, especially on the front cover of a photographers self promotion.

Job printed on 130# Silk Cover and run on a 3500, which also could not print the image square on the sheet. Seems the sheet was skewing through the machine and HP said 130# was pretty much outside the thickness they "support". Unfortunately, it seems that the shop that tried to print this could not fix the skewing problem as well.

There were 2 other components, I guess I could have gotten away with the postcard as it cut and packed and would have survived the shipping to the client where it would have been inserted into an envelope and mailed.

With Indigo's exceptional print quality (better than I believe to the Igen), other than a perfect bound book for example where sheets are not going to be handled so to speak, it seems you need to really pre-qualify the job for the Indigo.

Other than film laminating, anyone have any ideas? Maybe a uncoated or Gloss coated stock would have yielded better results.
 
Hey Signature,

I run a 3500 and know firsthand how hard it is to run 130# stock through that machine. Despite that being on the cusp of what that press can handle, there would be some other obvious questions.

First: Was the stock HP approved? In other words, was there a sapphire coating on the stock to enable the Electroink to adhere? I've ran a lot of material through my press that wasn't supposed to work and it did. And it did very well. However, there have been some stocks that just aren't suitable for the Indigo presses. The ink either scuffs off or won't adhere at all.

Second: There are some tricks that an operator can use to reduce scuffing such as adjusting blanket temperature. How experienced was the operator?

Lastly: Coated stocks will almost always scuff LESS than UNcoated stocks.

Unfortunately, sometimes a varnish or U.V. coating is required for some pieces. I can say without question that the Indigo is top of the line when it comes to quality but it is NOT a perfect machine.

Hope this helps in some small way.
 
Indigo

Indigo

Thanks for the thoughts. Just wanted to make ure i am not the crazy one.

Regarding stock, I am sure he got the cheapest stock he could get- it was Mohawk Loop, which I am sure was not sapphire coated.

The pressman had one week of training at Indgo and is really a desktop person, not a pressman.
Owner ran copiers then Igen before this and is clearly on the way to a step learning curve. They had multiple feeding problems, as sheets were jamming constantly, seems like when the machine sat for awhile and the room got warmer, the paper got exceasive curl and would not feed. After 5 hours 1 day, 3hours the 2nd day and 3 hours the third day, I gave up.

In addition sheets were skewing and not registering, and their paper cutter was out of square, and no color balanced lighting and consecutive proofs from revised files that never matched the previous run proof without adjusting color curves on press each time to add insult to injury.

Amateur night to say the least.

Hat type of jobs do you run that you are mostvsuccessful with?

Bill
 
I run #130 ALOT. Sometimes it is a huge challenge to get it through the press without scuffing. I am relating the following advise to what you described as far as scuffing AFTER the job was printed. First off if the paper is not certified you open yourself to all kind of problems. If it is certified paper you need to try to run the blanket temperature as hot as possible without burning out the screens. As far as the job not feeding into the press correctly and jamming on the way in. That can be caused by Headstops or stopfingers at the incorrect height. You will also probably need to adjust the feedroller everytime you run paper that thick. Make it push the paper more, move the number more positive. Also the fact that the sheet was not square means that it is never going to register right. If the paper is not square it could be dragging on the side guides which could cause jamming. It also will never back up correctly if the paper is not square.

Lastly an experienced operator makes a world of difference. The Operator courses offered at HP only cover the basics and VERY LITTLE actual running and troubleshooting is covered. As time goes by and your operator faces more challenges he will become better, but when a company chooses NOT to run certified papers, that accounts for 75% of the problems that he could possibly encounter.
 
Signature has hit indigo right on the money. It prints nicer then any other digital press but the fight they can not seem to win is the scuffing. If your ink build is over 300 percent you will have problems. When printing a solid on an igen you have toner issues along with fuser oil streaking. No matter the score you use it will crack. Indigo does a lot of nice stuff but there are a lot of jobs that we run that push the window of what it can do. It is hard to justify running 100 sheets on our SM52 because the rich black scuffs from the indigo but there are times we have to do this to get the job out the door. I see the biggest problem is the ink to ink adhesion. If you lay the cyan down first it will stick to the paper just fine. When you put the magenta down on top of the cyan ink then it does not stick so when you rub the ink you will see cyan because you rub the magenta ink off. Indigo has come a long way in the last five years and there will only be improvement.
 
Best plan is to trim the paper on the guillotine before putting through the press even if you are only shaving a millimetre off each edge,

I have tried just about every paper available in my time on indigos, if they want quality print they should use Indigo approved stock.

Remember if the jobs just solids keep the tempreture high, If the job is tints run the tempreture low,

I haven't ever had a problem with 130gsm apart from when I beta tested the 5000 press but an upgrade was made and that problem was erradicated.
 
Hi guys.

We are facing the same problem here on our Indigo, we are producing books on demand and covers are often scratched.

Can you recommend any particular paper type which is scratced "free".

Greetings from Iceland.
 
What is the TAC? (as RGPW17100 mentions over 300% is problematic) In many situations one is lured to think that 350% of canned profiles is not going to be a problem in digital since there is no drying issue… but that can be part of the problem. I know some say that digital should be 240% TAC. In some cases also maxing the colours at 98 or 99% leaving a small dot can help hardening the surface of solids. Also consider the screening may be pumped to overdrive not giving enough paper between dots to let the "ink" harden.

Ofc paper and temperature have their part to play.
 
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We stay with approved stocks only and print test new ones before we add them to our own list of approved stocks.

The Silk stock is a big factor in the scuffing in your product. Try it back to back with a quality coated sheet and see the difference for yourself.

When more scratch resistance is needed run the printed stock through an offline UV coater applying a gloss coating. No more problem. A satin coating would work well also. A matte coating will show scuffs / scratches much more easily but might contribute to the effect you are looking for.

Film lamination is the most scratch resistant surface but coating is more cost effective.
 
Indigo cover scratch is a know issue without coater. For postcard, even you use the best certified paper, depending on the country's mail handling system, it may not pass the scratch test without extra coating.

Adjusting Blanket temperature and pressure had a little help in adhesive but little help to scratch resistant. The scratch resistant is mostly due to stock that you are using. To my understand, when I spoke to the stock merchant that the indigo certified stock have different "stars" on adhesive. Choose the most stars for this application.

Sapphire coating is a good coating but tends to turn slight yellowish after few months.

The best option is choose the best paper from indigo certified stock with the most stars such as fedrigoni digital paper have a very good adhesive and scratch resistant on this application but also very expensive. If not, just run thru a offline varnish coating which is a cheaper option.

A certified paper for indigo makes a whole different in runs.
 

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