Some quality issue questions

[gordo]

This is about art books printed on uncoated paper on a press run of 650.

1 - Is it normal or expected that areas of color would have defects like dust and paper fibres?

2 - if so would you tell the customer that will happen before you run the job?

3 - How many defects in such a press run is considered normal or acceptable?

4 - What is the term for running blank sheets through a press to clean the sheets prior to running the actual job?

thanks g

 

[Cornishpastythighs]

when running uncoated sheets we used to 'Dust and size' as we termed it, bascially run the sheets through the press using the blankets to grab onto any loose particles then lay down a very thin coating of ink Extender(size) on the last unit.

 

[Puch]

1 - Unacceptable, the printer has to take care of press room hygiene.
2 - Of course, not, the customer expects zero errors.
3 - Artwork must be clear of defects and artifacts.
4 - We call them "cleaning sheets".

650 examples is not a small quantity for an art book, today. I would consider it a 'mainline job', which means it has to be produced up to the industry standards, if not better, considering the (possibly) picky customer.

 

[SteveSuffRIT]

Was the printer a "fine art" book printer with experience and not a commercial printer?
The term for cleaning sheets is called dusting.
"Sizing" seals the sheet with a clear varnish.
If the customers specs did not request a specific quality level, then the printing trades customs on the back of the estimate/quote is the terms and conditions of sale.
Print quality defects like hickeys remain until they move themselves or are washed off.
Did the customer sign off on a sheet and was the defect present then?
Is defect obviously noticeable from normal viewing distance of 18"? NO LOUPE!

 

[gordo]

Was the printer a "fine art" book printer with experience and not a commercial printer?
The term for cleaning sheets is called dusting.
"Sizing" seals the sheet with a clear varnish.
If the customers specs did not request a specific quality level, then the printing trades customs on the back of the estimate/quote is the terms and conditions of sale.
Print quality defects like hickeys remain until they move themselves or are washed off.
Did the customer sign off on a sheet and was the defect present then?
Is defect obviously noticeable from normal viewing distance of 18"? NO LOUPE!

Thanks for clarifying the term. I just couldn't remember it. :-(
Yes, the printer was experienced in fine art book printing.
The customer was shown samples of jobs on the same paper. the samples did not have defects. The job was printed in a foreign country so the customer was only shown wet proofs - which did not have any problems.
The defects were "dust" and "paper fibres"
Yes the defects can be seen at normal viewing distances.
After the job was shipped and the customer complained the printer said that everyone knows that all uncoated papers have this problem.

 

[gordo]

Here are samples of the defects on uncoated stock. The scale is in millimetres. What are the causes? Is this acceptable? Would dusting the sheets have helped? Remember the run is only 650 copies. Would running the press slower have helped?

 

[Magnus59]

I would say this is the result of poor press hygiene and maintenance.
Contamination in the ink train and on blankets, probably not from the stock used for the job, but from jobs printed prior without attention to cleanliness.

 

[realaqu]

Here are samples of the defects on uncoated stock. The scale is in millimetres. What are the causes? Is this acceptable? Would dusting the sheets have helped? Remember the run is only 650 copies. Would running the press slower have helped?
View attachment 290945

looks like lint from the rag and dirt on blanket

 

[turbotom1052]

The defects, as mentioned, could come from many possible places. The most likely would be from the stock. Did you spec a particular stock, and if so was it a premium branded sheet? Did your printer say or imply that they would provide the paper, and that it would be of a known quality? Was the paper cut to press size from a larger sheet?
One thing thats important to understand is that a run of 650 sheets happens in the blink of an eye on a modern sheet fed press. You can only run a press so slow, before the slow press speed contributes to certain problems. On a run of 650 sheets, the very act of starting and stopping the press a couple of times, creates quality problems that may be even more visible than the defects you mention. Every time you stop and start a press up it has to re establish its running ink tack, and ink water balance.
The only ways to minimize defect free printing is to insure that all of the materials being used are of the highest quality. A suitable amount of paper needs to be provided to get up to color, and to have enough overs to cover frequent press stops when cleaning up these defects. It would be best if the paper did NOT have to be cut from a larger size, and instead run right out of the carton. If the paper must be cut to size it is imperative that the stock is "back trimmed" with a sharp knife, and that the edges are wiped down with a tack rag.
You as a customer should be willing to incur the additional costs that come with all of the measures I mention above. If you shop printing on price alone, disappointments like you mention are going to be par for the course.

 

[turbotom1052]

As far as dusting the sheet either before or during printing, i will say this.... Ive seen it greatly improve paper debris problems, and Ive also seen it do more harm, as a result of loosening up particles. Sizing of the paper can have the same effect. If you must size the sheet it is my recommendation that it be done as a separate pass, and allowed to dry, to give the inks the best chance of properly trapping!!! All of these additional steps can quickly ad lots of cost to a 650 sheet run.