Gravure tissue

Craig,

I only took on class in gravure in the early 70's so I know what is
involved but absolutely no expertise.

Some questions.

Do you prefer the burnt sienna color? Does the color matter at all?

I am making the carbon with 250 Bloom gel which is pretty high. Would that
be a benefit? You seem to say it is?

Would a thicker tissue be of a benefit? Again that is implied in your
comments?

Haenfstengle was about 2.4 mil as I measured some once. Of course that was
one sample. I can easily make 4 mil or better.

Ashless gelatin was used in making tissue for ceramic processes so I am not
sure why Autotype is using that. I could make ashless gelatin but it is a
pain and would run the cost up.

I assume that most plates need extensive retouch work before printing

Thanks for your comments.

--Dick

At 07:14 AM 3/7/2004, you wrote:
>Richard,
>It's very exciting that you would consider making a carbon tissue for
>gravure usage.
>I don't think you would cut into Auto monopoly to the extent that they would
>cease making their product, as it has a very healthy, if small, consumer
>base in Europe.
>
>The problem that has been brought up about Autotype's tissue, referred to as
>assh*les, is in my opinion, not a fault of Autotype's manufacturing, but
>created during the actual process of making a gravure plate, or to a lesser
>degree, during the sensitizing of the tissue. What people may be seeing
>could be air bells trapped during the ferrotyping of the tissue. Not to be
>confused with trapping air during laydown on the copper which results in
>visual air tracks (bubbles) in the stencil. These actually don't etch, and
>result in white spots on the final print.
>But, trapping small amounts of air during ferrotyping create areas of
>thinner gelatin, especially with Autotype tissue, due to it's low gelatin
>bloom. These thinner areas will etch quicker and finally blow out to form a
>"devil".
>
>The "star" like gunshot wounds to the plate viewed after etching were
>commonly referred to as "devils" in the Rotogravure industry. They are
>almost always prevalent in the shadow areas of the image because those are
>etched the longest and this is where the tissue is thinnest. Also, they are
>more of a problem when doing actual grain gravure due to the uneven surface
>of the plate due to the aquatint resist.
>
>The main reasons they occur are due to:
>1, dust contamination in the process of adhering the tissue to the plate
>during laydown.
>Even the best controlled environment will contain small dust motes which
>will get between the tissue and plate during laydown, causing a microscopic
>hole in the stencil that will start etching as soon as the plate is immersed
>in ferric. This continues for the entire duration of etching resulting in a
>creve-like hole.
>
>2. "free" acid contamination of the ferric chloride etching solutions.
>This is probably a more prevalent problem facing people doing gravure work
>today. The free acid will increase the rate of penetration by softening the
>gelatin where it comes in contact, usually at the site of a dust mote, where
>the gelatin is thinnest.
>Hunt Blue label Roto Iron ferric chloride, still made for whatever exists of
>the rotogravure industry today, contains a very small amount of "free" acid,
>but it is negligible for most of our gravure applications.
>If you are using a ferric chloride other then Roto Iron, you can be assured
>it contains much to much free acid that must be neutralized with a solution
>of ferris hydroxide.
>
>Both of these problems will at one time or another plague someone doing
>gravures. I've had a close look at Autotype tissue before sensitizing and
>have never seen any blowouts in the emulsion, though they may indeed exist.
>But I believe the two points stated above are a far more common cause of
>devils then holes in the tissue from the factory.
>I base this on 30 years of using many different tissues and having these
>problems intermittently with all of them.
>MaGraw Colograph tissue was probably the best controlled and finest tissue
>ever produced for photogravure. It went out of business in the mid 80's and
>sold it's coating machines and proprietary formulas to the German Carbon
>tissue makers Hansfstengle Gmbh. Hansftengle continued to manufacture the
>duplicate MaGraw product into the early 90's, when it was forced to shut
>it's doors. I purchased 19 rolls of carbon tissue from their last run, and I
>can say that the last run they was not particularly consistent in quality!
>But, at the time, it was still a better product then Autotype.
>My main gripe with Autotype's tissue is the gelatin and pigment ( iron oxide
>which is probably not as finely ground as one would like, as opposed to
>MaGraw's burnt sienna). The gelatin itself continues to be dubious, a much
>lower bloom then what was used in most pigment papers, hence the difference
>in temperature (lower) and shorter time (to control swelling and absorption
>of the dichromate) in the sensitizing process. It is slimy, course and not
>workable above 53 degrees F besides being notoriously thin.
>But, at the time being, it is the best pigment paper made for photogravure
>by default!
>Cheers, Craig Z.
>
>
>----- Original Message -----
>From: "Richard Sullivan" <richsul@earthlink.net>
>To: <alt-photo-process-l@sask.usask.ca>
>Sent: Saturday, March 06, 2004 2:37 PM
>Subject: Re: News from Bostick & Sullivan
>
>
> > Assuming this means gravure tissue, what is the gripe with what Autotype
> > produces? Quality? Price? Would folks be willing to re calibrate to a
> > different tissue. It is my understanding that Autotype dearly wants out of
> > making it. The risk is if I come out with it and they drop it, I am in a
> > pickle as I have then inherited the mantle. There would be no getting out.
> >
> > I have heard that some batches are plagued with what are in the trade
> > termed assh*les, tiny areas that cause asterisk looking pits in the
>copper.
> > This i got from a couple of gravure printers here in Santa Fe and also in
>a
> > book on gravure from the 30's. I believe they are caused by small pinhole
> > bubbles in the tissue. With this long a history it may just be an endemic
> > problem in making the tissue.
> >
> > Thanks for the comments.
> >
> > --Dick
> >
> > At 12:07 PM 3/6/2004, you wrote:
> > >I would like to recommend the production of gravure paper. Autotype could
>sure
> > >use some competition.
> > >
> > >Jack Reisland
> > >
> > >Richard Sullivan wrote:
> > >
> > > >
> > > > With the coating machine I am looking at other coated products like
>oil
> > > > paper, collotype film, albumen, etc. Comments welcome.
> >
> >
> >
Received on Sun Mar 7 11:21:54 2004