What is "lith" printing, anyway?

After reading the recent thread on this subject here, I must confess I don't
know what the hell "lith" means.

I used to think it simply meant extremely high-contrast prints, or prints made
from high-contrast negatives, since this is the type of processing used in
photolithography (see below). But now I can honestly say I don't know what it
mens.

By the way, a word or three on the word "lith". Pardon me if this bores any of
you, who already know all this stuff, to tears, but as a working
"lithographer" I feel entitled to give this (ahem) lecture.

By "lithographer", I mean I am an offset press operator. The fancy snob
50-cent version of this term is "offset lithography". I'll explain the
"offset" part in a moment, but "lithography" refers to the historical origins
of this printing process.

Lithography, which is still practiced by artists (not by commercial printers
like myself), is literally "printing from a stone" (from the Greek "lithos",
stone). In this process, a large rectangular stone is dressed flat and
polished smooth. The artist draws on this polished surface with tools
(pencils, crayons, etc.) which leave a greasy mark on the surface: these marks
become the printed image. The process is based on the principle that oil and
water don't mix. The image parts of the stone (the marks made by the artist)
are receptive to the printing ink, which is oil-based, while the non-image
parts are receptive to water, which repels the ink.

To pull a print, the stone is first covered with a thin film of water. Then
ink is spread over the stone using a brayer (roller). The ink only sticks to
the image areas, while the water repels the ink everywhere else. After putting
paper over the stone, the whole business is run through a press, making a
print. (You can see the impression made in the paper by the stone in a
lithographic print.)

"Offset lithography" uses the exact same process, except that nowadays instead
of stones, we use metal (or plastic) plates which are made photographically or
by laser imagesetters. Like the stones, these plates are perfectly flat: the
image area is not raised in relief, as it would be in letterpress printing (or
sunk beneath the surface as it would in gravure printing). Like the stone, the
non-image areas of the plate are hydrophilic/ink-repelling, while the image
areas are hydrophobic/ink-receptive. The printing press has one set of rollers
that apply water (actually a mixture of water and other stuff collectively
referred to as "fountain solution") and another set of rollers (the "form
rollers") that apply ink.

Why "offset"? Unlike stone lithography, where the paper is pressed directly
against the printing surface, an offset press first prints the image on an
intermediate surface, a smooth rubber sheet known as a "blanket". The blanket
then transfers the image to the paper. This is better than direct printing
because it keeps a lot of the water from being transferred to the paper, which
would make it quite soggy, and prevents paper dust and powder from grinding
the image off of the plate. It also makes the printing plates "right-reading",
rather than reversed as letterpress plates are.

Just a few more notes, to bring this to some semblence of on-topicness. I said
that the plates used in offset printing are made photographically. This is
where "lith" film came in: the pre-press person first shot the camera-ready
artwork in a large camera known as a "process camera", using lith film
(Kodalith, for instance) to create an extremely high-contrast negative with
only totally open areas corresponding to the black image, and totally black
areas of background. After being "stripped" (cut and placed on a masking
sheet) and "spotted" (where the inevitable dust spots were "opaqued out" by
hand using red paint and a small brush), the stripped-up "flat" was placed
against a photosensitized metal (aluminum) plate, "burned" in a plate burner
using an electric arc lamp, then developed. Plate development could be done in
ordinary room light (assuming you do it quickly) with a solution that removed
the plate's coating from the non-image areas, leaving a colored (purplish or
blue) image. Then the plate could be mounted on the press.

All this is pretty much a thing of the past. Our shop doesn't even use metal
plates anymore except for critical (like 4-color process) or long-run (
15,000 impressions) jobs. Like many printers nowadays, we have a direct
digital platemaker (DPM) which is networked to our other computers. This
machine uses lasers to image the plate material which is comes on a big roll
and is imaged, developed, dried and cut to size by the platemaker. After
making up the job using the design program of choice (Quark, Adobe
Illustrator, InDesign, etc.), we "print" the document to our DPM, which spits
out plates. These plates are polyester with a silver coating, black plates
with a silvery image. We print from them, then toss them. Other digital
imagesetters can make metal plates using a similar process.

Other printers use imagesetters to make film, then burn metal plates from the
film using traditional techniques. But the days of going through boxes of lith
film are pretty much over, which explains why the stuff isn't available anymore.


--
.... but never have I encountered a guy who could not be bothered
to make his own case on his own show.

- Eric Alterman on his appearance on Dennis Miller's bomb of a show
on CNBC (3/17/04)

"David Nebenzahl" wrote in message
...
After reading the recent thread on this subject here, I
must confess I don't
know what the hell "lith" means.

I used to think it simply meant extremely high-contrast
prints, or prints made
from high-contrast negatives, since this is the type of
processing used in
photolithography (see below). But now I can honestly say I
don't know what it
mens.

By the way, a word or three on the word "lith". Pardon me
if this bores any of
you, who already know all this stuff, to tears, but as a
working
"lithographer" I feel entitled to give this (ahem)
lecture.

Lots of snipping...

Lith printing, as refered to here, is the development of
conventional printing paper in diluted lithographic
developer. The result is not extra high contrast but a
curious effect of a very warm toned normal image overlayed
by a high contrast image. The effects of infectious
devlopment will also often produce speckles. Not all papers
work well. There is a tremendous amount of stuff on the net
on this process. The best book is one written by Dr. Tim
Rudman, I think its title is "Lith Printing". An Amazon
search for Tim Rudman as author will find it. He also hangs
out on the Pure-Silver and Alternative Processes mailing
lists and will answer questions.
Say hello to the other chickens...


--
---
Richard Knoppow
Los Angeles, CA, USA

What David describes is true lith printing. A different kind of
printing is also called "lith." Dr. Tim Rudman has the definitive book
out about this. Basically, you overexpose a sheet of appropriate paper
(sterling lith or some regular papers), and you develop by inspection in
very dilute lith developer. You then snatch the print during
infectious development occurs. Infectious development is approximately
logarithmic in speed. It can go quite a while with nothing happening,
and then bang! You'd better snatch the print at the right moment. You
can get very interesting results with this process, including very high
contrast, pixalated shadows, and wildly variable colors. Development
time is often 5 to 10 minutes, and I've even had to go to 40 minutes to
get what I wanted. You can see examples in a number of places,
including Rudman's book, Eddie Ephraum's Creative Landscape Photography
and elsewhere.

-Peter De Smidt

In article .net,
"Richard Knoppow" wrote:


Lots of snipping...

Lith printing, as refered to here, is the development of
conventional printing paper in diluted lithographic
developer. The result is not extra high contrast but a
curious effect of a very warm toned normal image overlayed
by a high contrast image. The effects of infectious
devlopment will also often produce speckles. Not all papers
work well. There is a tremendous amount of stuff on the net
on this process. The best book is one written by Dr. Tim
Rudman, I think its title is "Lith Printing". An Amazon
search for Tim Rudman as author will find it. He also hangs
out on the Pure-Silver and Alternative Processes mailing
lists and will answer questions.

Tim Rudman has an introduction to Lith Printing at

http://unblinkingeye.com/Articles/Lith/lith.html

--

-tony

http://www.shapesandshadows.com

David,

the others already explained what lith printing is, so I'm just going to
add a link to some examples:

http://www.moersch-photochemie.de/da...2/lektion2.htm

It's a lith tutorial in German...just click your way through to "Lektion
5". There are some more lith prints at http://pics.spyz.org/.

Cheers,
Tobias

On 4/2/2004 7:00 AM Tobias Begalke spake thus:

the others already explained what lith printing is, so I'm just going to
add a link to some examples:

http://www.moersch-photochemie.de/da...2/lektion2.htm

It's a lith tutorial in German...just click your way through to "Lektion
5". There are some more lith prints at http://pics.spyz.org/.

Sorry, I don't read or speak German. Isn't that a little presumptuous of you?


--
.... but never have I encountered a guy who could not be bothered
to make his own case on his own show.

- Eric Alterman on his appearance on Dennis Miller's bomb of a show
on CNBC (3/17/04)

David Nebenzahl wrote:
On 4/2/2004 7:00 AM Tobias Begalke spake thus:

the others already explained what lith printing is, so I'm just going
to add a link to some examples:

http://www.moersch-photochemie.de/da...2/lektion2.htm

It's a lith tutorial in German...just click your way through to
"Lektion 5". There are some more lith prints at http://pics.spyz.org/.


Sorry, I don't read or speak German. Isn't that a little presumptuous of
you?




No, it's not, since the responder clearly was citing the site as
providing examples of lith printing, which would be useful even if you
don't speak German. If this is how you respond to people trying to be
helpful, then people will stop being helpful.

-Peter De Smidt

David Nebenzahl wrote


By "lithographer", I mean I am an offset press operator.


I was one of those. My job ended with work at the press; Multilith
IIRC.
Prior to the press I took the pictures. The film and 4x5 print
processing was farmed out. With prints delivered I was back at work
making ready copy, tacking lith film to the stickyback, setting the
screen, etc.
Following that was the lith processing which included checks for
correct dot formation. I did not burn the plates but did do the rest
through a press run. Dan

David Nebenzahl wrote

By "lithographer", I mean I am an offset press operator.

Oh. How disappointing. I thought you did the old stone litho stuff.