printing halftones

How do I do this? I have done some reading in the Hiedelberg manual about rubber blankets for makeready. So how how do I get them to print well? I have one in a photopolymer plate and it just printed like a solid silhouette without the detail of the object within it.


Thank you in advance :).


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Meaghan -

Well, the first thing about printing halftones is that they are a case where the old ‘kiss impression’ is key. Although printing a halftone does require a lot of pressure, due to their nature - and all of those little dots, halftones will not print well if punched at all. And, due to the technical challenges of printing halftones - or four-color process - on a platen press, it seems to me that just about the only people who really took those capabilities seriously were the technicians at the Heidelberg plant.

Of course, that is not to say that it cannot be done or should not be done - just that it’s hard to do well and is not the best application for a platen press.

That said, I have printed halftones on my platen presses in the past and I have printed 4-color tight-register pieces and both *can* be done. But this is where that magic combination for just the right ink, just the right paper, just the right plate and just the right packing all come in to play.

The plate must be perfect and the screen should be relatively coarse. The paper should be very, very smooth - coated stock is recommended, the packing just right (yes, that special Heidelberg rubber packing sheet can help) and the ink should be very, very soft so that just the right amount adheres to each dot on the plate. If the plate prints as a solid, wash off most of your ink and try again. Add ink sparingly, and increase the impression slowly.

Remember, when printing a halftone, it’s just a bunch of dots placed closely together… It is not easy and should only be attempted as a test. There are far better technologies available for printing photographs than any platen press.

The platen press is great for text and line drawings. It is not a good press for printing halftones.

But - one final word…. The last place that the old Washington Hand Presses were found and where they were still used commerically through the 1950s were in the photo-engraving shops where they were the presses used to print proofs - of both line art and photographs… But they were operated by experienced printers and engravers who had many tricks up their sleeves. And, the Washington Platen Presses were eventually replaced by Vandercook Proof Press, which *can* print halftones very well.

I thought this might be a great challenge and I have been told that todays print technology handles these things much better. I think I will take my artwork and convert is to lineart (where I can) and avoid this type of work (however I still might have a crack at handling it on my press :). )

So sounds like my next press will be a Vandercook proof press :).

Just because some would see halftone printing, using a platen press,as difficult (it really isn’t), don’t believe you cannot achieve success in that doing. Yes, there are definite skills which must be applied but, as with any challenge, preparation is key. To that, research the halftone field; explore the many options available to you in producing pleasing result. To encourage you, remember that thousands upon thousands of county shops produced excellent halftones under the most primitive condition. That it was perhaps difficult certainly did not dissuade from that doing. Of course a cylinder press will give superior result to that of a platen - its very design lends to that achievement - however, even the lowly Kelsey 3x5 platen will print acceptable halftones. If, that is, adequate knowledge and correct application thereof is followed. Looking at your first halftone will encourage you to work toward process printing; and a step along that path will reveal the delight of Duotone reproduction. The Black Art has many challenges - I suggest you not become discouraged simply because someone suggests it might prove a difficulty. In my opinion.

Updated. Hi Meagan,
All the comments are right on. We would match the “screen” = (DPI) to what paper we were using. DPI = dots per inch, and screen =“lines” per inch as in a window screen
Hot type newspapers printed acceptable photo/halftones with +- 65 screen on newsprint/foolscap. In the job shop with only platen presses we used about a maximum 120 screen for most things, but that needed to be printed on a coated paper preferably or sometimes on a filled and calendared paper. 180 screen is about the best quality screen I’ve printed, but that was on a Miehle V50 cylinder press. Printing any size halftone is a piece of cake on a cylinder press.
Short ink prints easier. We used a reducer that came in 1/4lb tubes. You only used about a large cap worth at a time on a 10x15 C&P., about the same on the Heidelberg. The tube lasted a long time.
Impression is also critical. It has to be more kiss than punch.
If you are considering another press put the Miehle Vertical V50 on your list: 3 1/4 x 5 ½ to 14 x 20 sheet, minimal if any make ready, and runs all day long at 3-4000iph. Great easy to learn and operate machine with a small footprint.
All that you have learned about paper handling, fluffing, separating, inking, impression and so on will carry forward to your next automatic press. From now on you’ll only need to learn how to make them “go”.
I envy you,