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mrpengun
4-Jun-2009, 20:39
So, maybe I've just missed a trick somewhere along the way, but I was wondering if anybody is using some sort of lithographic film in order to make... you know... lithographs?
I've been googling, and lots of folk seem to many other uses for ortho-lithographic films, but I am yet to find anybody detailing their use of lithographs with them...

and while we're on the subject of my ignorance regarding lithography, does that require the developed film to produce some sort of "relief" in order to transfer the image onto the lithographic plate? Or am I confused again?

Gene McCluney
7-Jun-2009, 00:55
So, maybe I've just missed a trick somewhere along the way, but I was wondering if anybody is using some sort of lithographic film in order to make... you know... lithographs?
I've been googling, and lots of folk seem to many other uses for ortho-lithographic films, but I am yet to find anybody detailing their use of lithographs with them...

and while we're on the subject of my ignorance regarding lithography, does that require the developed film to produce some sort of "relief" in order to transfer the image onto the lithographic plate? Or am I confused again?

Lithographic plates, such as used on offset presses are exposed to UV light thru contact with a high-contrast negative made on ortho-litho film which was developed in high-contrast developer yielding a black-and-white negative (no shades of gray). The offset printing plate hardens in areas where the film is transparent-and light is transmitted thru the negative to the plate, and the remaining emulsion on the plate is washed away in a processing step after exposure leaving an image that can be inked and printed. It is a photographic process. The film does not have a relief image, only the printing plate, and one is not needed. The emulsion on the printing plate is such that the remaining image will attract ink and the base of the metal plate repels ink when damp. Normally only type and graphics are exposed on ortho-litho film, and a photograph has to be copied to litho film thru a screen which will render the image into small black dots of varying size, simulating a continuous tone image when printed.

This is all completely different from the alternative use of ortho-litho film as a continuous tone, full-tonal-range film for pictorial photography purposes when developed in a highly compensating soft-working developer. In this case the full-toned negative is treated just like any other photographic negative and contact (or enlarger) printed on conventional photo paper yielding a conventional b/w photo print.

mrpengun
7-Jun-2009, 07:58
That does make more sense that the plate would be light sensitive as well.
The question remains though; has anybody used lithographic film to make a lithographic plate? I ask, because i may be trying to in the coming weeks. Google found a pretty good resource/shop called "Graphic Chemical and Ink" in Villa Park, IL, which has a wide selection of plates etc, but any first-hand disinterested experience would be lovely!

erie patsellis
7-Jun-2009, 08:34
I use it at work all the time to make printing plates. A good UV light source is important, as well as a vacuum frame. Google printing plates and you'll find a wealth of knowledge (buried as usual with the garbage)