Hi fidelity printing / micro dots

[Lukew]

Having an interesting discussion the other day with a friend regarding hi fidelity printing and the ability to transfer and hold micro dots from plate - blanket - substrate and what is the current limiting factors that make this process difficult for some to achieve.
His thoughts were that even if the plate can hold the micro dot, the chemistry used on the press will effectively wash the micro dot off the plate and not allow it to transfer to blanket and then substrate.


Anyone out there currently transferring to substrate micro dots that could make text characters invisible to the naked eye, but visible under microscope without issues of dot loss or failing to transfer?
What are your thoughts on the current limiting factors?

 

[gordo]

Having an interesting discussion the other day with a friend regarding hi fidelity printing and the ability to transfer and hold micro dots from plate - blanket - substrate and what is the current limiting factors that make this process difficult for some to achieve.
His thoughts were that even if the plate can hold the micro dot, the chemistry used on the press will effectively wash the micro dot off the plate and not allow it to transfer to blanket and then substrate.

A conventional offset press - not new, not in perfect condition - can do 20 micron FM and possibly 10 micron if the image is on the plate.
On a sidebar, the resolution of press blankets is on the order of 0.5 microns for the smoothest to 3 microns for the roughest. So, as a reference scale, a 1% dot at 240 lpi is 10 microns which is huge relative to the resolution capability of the blanket. When I worked at Creo we would often use micro text to create a "discoverable" message in some of our marketing materials. So, you might see what looks like a 1/4 rule graphic in a brochure but under a high power loupe you'd be able to read a text message. We had no problem imaging a 10 micron pixel on the plate and see it appear clearly on the press sheet (Creo used to sell an ultra-high resolution CtP device for security printers which could do the same but imaged a 5 micron pixel - 1/4 the size of a 10 micron pixel)

Anyone out there currently transferring to substrate micro dots that could make text characters invisible to the naked eye, but visible under microscope without issues of dot loss or failing to transfer?
What are your thoughts on the current limiting factors?

I've done it in a conventional production environment.
I've set up printshops to do it in conventional production environments. At Creo we had a few customers who printed all their jobs using 10 micron FM - on all their substrates. Canadian stamps (and many foreign (to me) stamps are printed with 10 micron FM. Hallmark greeting cards used insist on that screening (don't know if they still do). Much of Nike's corporate marketing is also printed 10 micron.
The limiting factor is the attitude and culture of the print shop - not the technology.

 

[Alois Senefelder]

Gentlemen,


The Surface Topography of Aluminium Litho Plates.


We need to remember three fundamentals regarding Image Resolution on litho plates.

1) Electro-Chemical Graining. 2) Anodic Layer. 3) Photopolymer Image Coating.


Regards, Alois

 

[gordo]

Gentlemen,


The Surface Topography of Aluminium Litho Plates.


We need to remember three fundamentals regarding Image Resolution on litho plates.

1) Electro-Chemical Graining. 2) Anodic Layer. 3) Photopolymer Image Coating.


Regards, Alois

You didn't list - "desmut"! That's a highlight among some folks LOL.
The pits on a litho plate resulting from the plate manufacturing process are typically smaller than 3 microns but those carry the water not the imaging ink. The coating that carries the ink is typically much smoother.

 

[Alois Senefelder]

alibryan...........



"Being a ----- on the internet because you can. Typically unleashing one or more cynical or sarcastic remarks on a

contributor, because it's the internet and you can"


" You are entitled to your opinion. But you are not entitled to your own facts" Daniel P. Moynihan


Alois

 

[Green Printer]

I hope this goes further this is fascinating.

 

[Green Printer]

Folks I suggest you be quite on the details of this process you are getting into governments worldwide guarded trade secrets for currency, passports and many legal documents reproduction.

 

[Lukew]

Lets make it clear. This was not intended to be a discussion on how a particular process is achieved as obviously there are going to be a lot of guarded secrets. It was intended to be a discussion on what others feel are the current limiting factors in some pressrooms to achieve micro dot transfer.

 

[gordo]

Lets make it clear. This was not intended to be a discussion on how a particular process is achieved as obviously there are going to be a lot of guarded secrets. It was intended to be a discussion on what others feel are the current limiting factors in some pressrooms to achieve micro dot transfer.

So, as I wrote before: "The limiting factor is the attitude and culture of the print shop (e.g. management) - not the technology."

PS - There seems to be a great deal of animosity directed towards member "Alois Senefelder". If you knew him you would realize that it is completely unwarranted.

 

[gordo]

I think actual experience holds more value over random (or direct) internet searches and in a reply to you, I posted that opinion. It may have been deemed inappropriate by some - and I apologize for that, but I still believe that what I said is the truth. Out of respect to this forum; I've since withdrawn that post.

Interesting. I don't think you should have withdrawn the post - nothing wrong with questioning the credibility/expertise of the posters on this forum regarding a specific post. Just make it clear who you have an issue with. Since it now appears to be a comment about me rather than Alois - that's great. What is your specific issue with what I've posted?

BTW, I don't hide behind an alias - anyone can check my history.

 

[Lukew]

Hypothetically, Lets run with the following, same press, same plates, same blankets, same paper, same ink. With only one difference. One is transferring micro dots, one isn't. What do you think is the prohibiting factor and why?
Gordo, I understand what you saying. It is possible with the correct set up.

 

[gordo]

Hypothetically, Lets run with the following, same press, same plates, same blankets, same paper, same ink. With only one difference. One is transferring micro dots, one isn't. What do you think is the prohibiting factor and why?
Gordo, I understand what you saying. It is possible with the correct set up.

Well, you left out fountain solution Which is the barrier that your buddy mentioned. Fountain solution is effectively a solvent so, yes, that has the potential to over-emulsify the micro dots and cause failure.

But if the setups are the same then they should both either fail or succeed equally.

What are you actually asking or trying to accomplish?

 

[Lukew]

Im not trying to achieve anything. It is though an interesting subject.
I'm sure from your experience you have a thorough understanding of what can be the reasons some pressrooms fail to achieve the subject above.
Yes true I believe fountain solution can play a key role but then there is ink. Which is some cases won't transfer micro dots

 

[gordo]

Im not trying to achieve anything. It is though an interesting subject.
I'm sure from your experience you have a thorough understanding of what can be the reasons some pressrooms fail to achieve the subject above.
Yes true I believe fountain solution can play a key role but then there is ink. Which is some cases won't transfer micro dots

Doesn't have to be micro dots. Any area of very little ink coverage can result in ink not transferring - hence the need for "take off" bars.