Good proof press for halftone?

A good proof press in the hands of a good printer who understands the process will give good results from a good halftone that is not damaged. Some proof presses may be better and you can pay a lot of money for a Vandercook. If you are looking to do single color work, you can pay much less.
Look to see if the press is in good condition. Rust or dirt are not deal killers if there isn’t too much. Does the cylinder traverse the bed smoothly? Is the cylinder free of damage? Most proof presses that were intended to make proofs of type were intended to have the type in a galley. If your halftone is not in a galley, you will have to build it up by .050” Quite simple to do with a couple sheets of chipboard or press board +/- a couple sheets of copy paper as needed. You need not measure the underlay. You determine the correct amount by test printing. Much as you would do for platen makeready. The cylinder is to have a sheet of typman paper around it. You apply the ink to the halftone with a brayer. Very little ink and very lightly applied.
For halftones a harder rubber brayer is better than the nice soft rubber you want on platen press rollers.
Experiment
Enjoy
Get some ink on your shirt

I am going to start with single color and probably move on after a long while to more. Keeping it simple at first so that I can learn the basics.

Unfortunately I am not looking at the proof press in person but taking the sellers opinion. I will ask those questions and hope that he is accurate. I have done well fixing most problems with other pieces of equipment that I have bought so not terribly worried.

I appreciate that info on the difference in height to account for the galley which it appears to have been what its intended original use was for.

Can anyone give me insights into pros vs. cons with proof presses that the bed moves vs. the cylinder moving? Seems that the more pricey models have the cylinder moving.

A reproduction proof press, or test press, like the Vandercook SP15 or SP20, can make the best proof of a halftone. Challenge also made a similar press, which may not be as pricey as the Vandy. But a Poco #0 (which I have) can also make a very creditable proof, though it lacks grippers and multi-color register work is much harder on it. The sign presses, if very carefully prepared and used, and in good condition, can also do creditable work. You’ll want a dull-coated paper for the most satisfactory results. Depends on your budget. You can probably get a Poco for around $7-800 and a Vandercook for $7-8000. Choose your poison and do some printing!

Bob

I am painfully aware that the Vandercook is the best loved and of course priciest. The proof press that I am eyeing is asking $400 and seems fair as long as it is capable of doing reasonably good work. Which is good enough for me the hobbyists. I don’t mind tweaking to get the best results. Sort of the fun but don’t want to be spending time and money if this is just not suitable for even fair-good work.

Thanks for the responses so far. (Didn’t say that before.)

The cost difference between stationary bed and stationary cylinder? Just expectations, and expectations drive price these days; not availability because there seem to be more Vandercooks still in use than other makes, yet prices keep rising.
Vandercook made only stationary bed machines, and they are what most people learn on now and therefore what most people desire. Challenge made both types of proof press, and though most are not high-end machines, they are probably equal to the (cheaply-made) SP Vandercooks. For stationary bed machines, Hacker and Claybourne made presses equal or superior to Vandercook. There just aren’t many of those left.
The overall condition of the press, and design features such as an inking system and grippers are more important than whether the bed moves or stays.

And, just because I am now biased as all get out, I have to promote the Potter. (made by Hacker) If, it has everything intact it is another good choice. It is in the stationary cylinder group and capable of fine work. My Potter No. 3 is now 99% finished as seen in the photo.

100_4236edit.jpg

come on John, they weren’t even that clean and shinney right out of the crate.

parallel_imp that was the exact info I was looking for.

Also love the photo of the potter. I think that this basic challenge press is a good start then and if I fall in love with the cylinder printing processes I will search for a unit with an inking system and the such.

Reliance and Washington presses were built and made for half tone proofing in the engraving houses turn of the century. I would recommend one of those for proofing half tones(and printing depending on the run).

Thanks Michael, I will look into those as well. My runs will be very short run so those may work even better.

Some of the Washington-style handpresses made for photoengravers were not type-high, may not have had friskets either. (Not that there are that many still out there, compared to cylinder proof presses.)

Have you tried printing the half tones on your C&P? It is possible. Are you using PhotoPolymer or copper/zink? A key thing to determine is how high of a line screen you would like to print. This will define some of the parameters and what kind of press is best.

Also, Many sources recommend printing image and type in separate runs for fine work. In which case you would not necessarily need to be Type-high for the half tones.

Really, printing haftones is a complicated process. Once you have a well-made halftone plate, then precise makeready and suitable stock is an absolute necessity. The screen resolution must be suited to the stock (the ink too). The coarser the paper, the coarser the stock [that should have been “screen”] needed.
Makeready time is something that helped drive the industry from letterpress to offset. Making ready a 60” cylinder press for a complicated form could take longer than the actual running time, even on long runs.
The essential part of makeready for a halftone is the overlay, which adjusts pressure for the different values in a halftone: less pressure to the highlights, more pressure to the shadows. Originally the method was to cut overlays by hand, but different processes for mechanical overlays were developed. About the only mechanical process you could duplicate today is the “biscuit” overlay, which just needs varnish and flour and shellac. Chalk overlays and 3M overlays and other patent systems require materials have been unavailable for decades.
On the other hand, Vandercook developed a system of very precise platemaking and plate mounting called the Mimimum Makeready System. It involved making permanent underlays to compensate for defects in the press, then making very precise forms. Perhaps photopolymer can provide that kind of precision today. Unfortunately, the system also assumed very smooth or even coated paper. If you went to Vandercook then and said you wanted to print halftones on something like today’s Lettra, they would have thought you were insane.

And they would be right to think so, IMHO.

Using photoshop curves/adjustments and flattening/posterizing methods, however, to make something like image-on (a somewhat thin photopolymer film) or some other photo-sensitive polymer into an underlay couldn’t really be that difficult once a workflow was established. If you generated the film for the underlay and the film for the plate at the same time- developed each- found a way to register it to the cylinder…. It’s a lot of work, but it might be quicker/easier than doing large amounts of careful tissue underlay. Just a thought really, but not an impossibility?

Luckily we have a greater selection of papers than just Lettra ;)

Proper Makeready is going to be essential. The biggest time saver is having a well screened block(which takes an exceptional positive/negative). Unless you are crazy like me, you will probably be screening things digitally with photoshop or acrobat(unless you have a RIP). Havenpress, is right about using photoshop to manipulate the imagery. This may take just as much time as makeready on press but, you can manipulate the image so that it screens to print great with minimal overlays/underlays. If you are using Photopolymer , you can mark the plate directly and ad underlays of adhesive or paper. Some may find this easier than working on the platen. If you are working through the lens screening can get quite complex but it is possible to create a really great block that also takes minimal over/underlaying.

Don’t be intimidated if it doesn’t turn out perfect first go. Start with a rough screen (65 or 85 lpi) and work up to finer screens. There is a lot to learn and know about making half tone blocks. I am excited to see more interest in bring it back to letterpress(not that I don’t enjoy really great line work).

-best of luck

Computer generated half-tones have square dots, where the older camera-generated half-tones had round dots. The difference in clarity is enormous. For a better reproducing image searching for a supplier who uses an old style camera would be an excellent idea.

Paul

parallel_imp

I have read something to the effect, in regard to your overlay information, that photopolymer plate halftones actually incorporate something similar to what was practiced in those long ago years when photoengravers actually worked the plate. That is that the surface of photopolymer plates vary in depth slightly in regard to surface proximity, providing a similar response.

Not sure where I read that, not sure it is valid.

Gerald
http://BielerPress.blogspot.com

I dug through the archives over at PPLetterpress and this is what I found in that regard [this is correspondence between Harold Kyle (Boxcar Press) and myself].

[Gerald]
In discussing the BASF plate:
“An interesting fact about the new plate is that, due to the particular molecular structure of the material, a form of built-in make-ready is provided by the fact that the highlight areas are fifty-thousands of a millimetre below the heavy tone areas.”
I think you had mentioned something like this a long while back but I have never otherwise found it in the literature.

[Harold]
I have a promotional booklet for Nyloprint plates that mentions this phenomenon. My Jet rep says the microscopic swelling of dark areas is common
to all photopolymer plates. This is supposedly why halftones require less makeready with photopolymer.

Gerald
http://BielerPress.blogspot.com

I can’t resist adding to this. Think about such subtlety, if valid, and then think about deep impression. Sort of a brutal waste of an incredible technology.

Gerald
http://BielerPress.blogspot.com