Packing - Please Explain

After reading all Afternoon through the archives I do not know if I’m more knowledgeable or more irritated…

I try to understand what the packing is for. What is it’s purpose?
Why tympan sheets for the top? What characteristics do they have, that other papers do not have.

It seems there are 2 sorts of packing: soft and hard. Hard seems to be the choice for deep impression.

I have bought a Heidelberg Windmill, downloaded the manual from Boxcar and read it, I read through the archives and other online-information, but I still don’t get the purpose and the “art” of packing.

Can someone here please give me a detailed “The Purpose and Art of ‘Packing’ for Dummys”-Explanation?


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Others will likely be able to explain this better than I and any of the standard books on the subject can certainly do so but here is some information that may be helpful.

If all one used was the form and the sheet of paper to be printed with a bare platen the form would likely be damaged and even if it wasn’t it would be difficult to get a good, consistent print. This is because no form is perfect, there are always other irregularities, and different weights of paper are used for printing. So there needs to be a way to regulate the amount of impression. Further, the sheet to be printed must be held in place securely and this done in such a way that it always registers in the same place.

The platen is therefore packed out with sheets of paper of various weights or sometimes other materials such as mylar. Because a better print is obtained when the sheet to be printed is backed up by a hard surface, these sheets of paper are of a type that are hard, smooth, and consistent in thickness such as pressboard, sized and super calendered book, tympan paper, etc. In other words, a hard packing. In most cases a hard packing is always preferable because it will put less wear and tear on the form and allow for crisp, clear prints. A soft packing allows the form to press into it and wrap around its otherwise crisp edges, thereby wearing or rounding over those edges, among other evils. It is generally used only in special circumstances.

The different weights of packing paper are used in different combinations to acheive the thickness needed to print successfully a given form with a particular weight and type of paper. Therefore these sheets are usually loose because of the need to remove or insert them to adjust the thickness of the packing and the quality of the print. In other words, with no packing on the platen and when the platen is closed there will still be a certain amount of space between the face of the platen and the form. That space is “packed out” to whatever degree will acheive a proper print.

In order to hold these sheets in place on the platen and to provide a fixed surface on which to attach the gauge pins that hold and register the sheets to be printed, a topsheet is used that is large enough to be clamped under the bails of the platen. The top sheet, also called the tympan, needs to be hard and smooth as well as durable. A trial impression is usually pulled on the top sheet, the ink being wiped off leaving a “ghost” of the form, in order to have a means of laying out the margins and setting the gauge pins. To meet these requirements an oiled manilla paper, tympan paper, is made especially for this purpose.

I believe the Heidelberg has its own requirements and needs for packing and I don’t know enough about it to comment. The above applies to most platen presses and for the most part to cylinder presses such as the Vandercook, with some variations.

On a regular platen press such as a C&P, the platen must be adjusted to not only be parallel to the bed but also to accommodate a “standard” thickness of packing that will allow for adjustment by adding or removing sheets without going crazy. Remember that no matter what kind of paper is used, the thicker the packing the softer the packing. The idea is to find a happy middle ground incorporating the right kind of paper, enough variations in thickness to make adjustments, and still keep the thickness to a minimum. For this purpose, a traditional packing is:

1 sheet tympan as top sheet.
1 sheet red pressboard.
2 or 3 sheets tympan or index. Tympan is better.
3 or 4 sheets book paper.

This is the usual order from the outside in towards the platen and is the place to start. It would be used to dress and then set the platen using any of the standard methods. Of course, many people use what they have, me included. I have a couple new rolls of tympan I got from an old shop which I use for the top sheet, but they are both .012 thick. I don’t have any sized, super calendered book paper so I usually use .006 tympan paper and perhaps a sheet or two of bond paper.

Looking at old presses with the platens still dressed I’ve seen other kinds of packing that I could not even recommend but that seemed to work for them, or maybe not. Anyway, I try and come as close as possible to the ideal with the understanding that there are always options and differing opinions and the inevitable work-arounds.

I didn’t mention makeready as that is another whole subject.


Front Room Press
Milford, NJ

The actual manual for the windmill has samples of packing at the end, but they probably aren’t what people are using today. They were using manila/kraft as topsheet, one or two sheets of index bristol at the bottom, a sheet of manila/kraft or book paper as makeready sheet (where spot packing is glued), several sheets of smooth newsprint above the makeready sheet, and for halftone work a thin rubber blanket below the topsheet. The Windmill has a very limited range for packing materials, unlike most other platens: manual says 1/25th of an inch, including stock to be printed.
Real tympan paper is like manila but is oiled for durability and some resistance to ink, might be antistatic too. Topsheets or Drawsheets are carefully sized to fit under all the clamps, reels of a particular press. Hanger sheets go underneath and are only held under one of the clamps, other types of packing are just loose. Tympan is used as topsheet and as hard packing underneath; pressboard is used as hard packing; traditionally, smooth book paper is used as medium and newprint as soft packing, but all kinds of material can be used for different purposes: film, litho plate, tracing paper, onionskin, glassine, blotter. Some softness is needed where forms are not perfectly level, as in metal type. Many use mylar or the like in place of oiled tympan, which does compress a bit with use and must be changed regularly.
Spot packing is paper added, in register, to compensate for low areas or other areas needing extra pressure such as solids. People often just refer to this as “makeready” and the knife used to shape it as a “makeready knife” but makeready can refer to a lot of other things as well. How much effect the spot packing has can be varied by its position in the packing. The lower it is, the more subtle the transition. High up, you may see the steps between the extra layers of paper.
The reason hard packing is used for heavy impression is to force the paper to compress rather than force the paper into the compressed packing with resulting bulge on back. But what will work for any given job varies with form, paper stock, and the press. I heard of a windmiller who doesn’t even use drawsheets, but just glues spot packing right on the platen, a technique taken from foiling and embossing.

Wow, thanks a lot for this very detailed information. Exactly what I was looking for.

So the Packing was traditionally a means to guard the type, since the paper/board in the packing is softer than metal, but could be hard enough to get a crisp print. Right?

And additionally for different paper stock I would need a different packing, which I have to “trial and error” before starting the print run?

And as I understand it, if I want to have a visible imprint on the paper I need to have hard packing, so the form (Photopolymer Plates in my case) or the paper has some resistance.

I need to set up my Windmill and start experimenting.

Again thanks a lot

Hi, Mirko—I’ll make a start.

Your Heidelberg is engineered to close on impression with a packing in place to add .030 - .040 inches to the height of the platen. So there is, first, a mechanical expectation that you will use a packing to make the surface of the platen roughly parallel to the surface of the form at typehigh.

The iron platen (iron, I think) would also be much too hard for printing type forms on paper. So the packing acts to protect the type, and to a lesser extent, the surface of the platen.

Besides being useful for pulling an impression on, or for affixing the guides to a C & P, The packing is useful for controlling the impression. It can be made thicker to increase impression at the bottom of the form, or thinner, to increase impression at the top, relative to the bottom. On the Heidelberg, which has an impression adjustment as well, the ability to adjust both is very handy.

As you discovered, the use of various materials in the packing can produce a “soft” or “hard” impression. It is also possible to place materials selectively in the packing which affect only part of the form. This “makeready” can increase the impression on a heavy cut or large type without altering the impression on a fine rule or light type.

Packing materials are made to uniform thicknesses and hardnesses—they are standardized, and if precut to the platen, can be changed very quickly. On the other hand, you can experiment with a wide range of other materials for various reasons. I have tried, at one time or another, rubber dental dam, cloth, mylar, chipboard, and probably other stuff too.

For a “normal” Heidelberg packing, I use something like (top down): .006 inch oiled tympan, one or two .003 draw sheets, fastened with the tympan under the bottom bail, and then filler of manila tag and .005 or .007 mylar loose in the packing to reach .035 or thereabouts. I adjust this as needed as the makeready continues to get the impression I want.

The purpose of the in-place draws is so that you can pull a light impression on a sheet of stock, hold it in place in the guides, stab through the sheet into the packing with your makeready knife, open the packing, and place the printed sheet in register with the form by putting it to the stab marks in the draw. Then the makeready that builds up those parts of the form that require selectively more impression can be placed under the tympan on the printed “spot” sheet.

There may be some information useful to you at:

Other pressmen and women will have other favored methods of packing. I would hesitate to say there is one right or best way.

Good luck, Brian

on the windmill you have a packing gauge, it is on the top of the delivery on the right side, your packing must fit snug in this gauge. this is in the manuel. good luck dick g.

Protecting the form is one function of the packing. On Gordon-style platen presses it is also a means of regulating the amount of impression. It is also a means of mounting the sheets to be printed and maintaining registration while doing so.

One doesn’t need a different packing per se but a different thickness of packing depending on the thickness of the stock on which you are printing. One adds or removes sheets as necessary from the basic packing used to set the platen. It should rarely if ever be necessary to adjust the platen once it is set correctly.

It is trial and error but not without a foundation from which to begin. You want to take a slow, single impression, usually by hand, in order to make a test print. It’s better to start out with a light packing and then work your way up in order to avoid accidently damaging or locking up the press by starting too thick.

A hard packing should “always” be used especially for a deep impression (there are some exceptions). The reason most people doing deep impression use the medium weight Lettra paper (#220) or something similar is because it is thick and therefore has enough “depth” for the form to press into it without punching out the back. To achieve this you need a hard surface behind the paper to support it, otherwise the form will press the paper into the packing.

Keep in mind that deep impression even with a hard packing will unnecessarily wear metal type and cuts. Newly made forms can be replaced but not old foundry type or vintage cuts. Please don’t use these things when doing deep impression.

Remember that the Heidelberg may have completely different setup needs for the packing, one reason being that the impression is easily adjusted mechanically during the run unlike Gordon style platen presses. You need to follow the manual and ask specifically for help from someone who knows those presses. But knowing the general principles is important.


Front Room Press
Milford, NJ

These are all very good info and help to bring some light into the packing mystery for me. That’s exactly the reason, why this Forum is so highly recommended. Thanks to you all.

Is there something like a FAQ-Section on this board, so this thread can go in there?


Hi Mirko,

That’s a good suggestion. Here at Briar Press we’ve been thinking about similar ideas for a while now. I’d like to create a place where the most viewed or most useful discussion topics could be found.

Nothing like that exists here at the moment, but I’d like to make it part of the next site upgrade. Thanks for the reminder.



Remember what you have bought was not designed for the hobbyist.

It was designed for long runs, running all day (sometimes 24 hrs), producing something like 3500 iph, not the few prints that a hobbyist may produce.

At this rate of production “Deep Impression” was the sign of an inexperienced craftsman; I worked Heidel windmills and cylinders for 50 yrs and we only ever used a kiss impression for printing.

Normal founders type would not last very long with a deep impression!


I know the Windmill is a pro press. But I will learn how to print with letterpress and also how to tame the “windmill”. I hope from my question you can see, that I really want to learn and understand. I’m not just into the quick letterpress revival experience. Btw we had a windmill at the university where I studied design and visual communication.

For my purpose the windmill might be to big, but first I love to own one (hey, I’m german why not admire german craftsmanship ;-) ) and second for 500 Euro (approx. 700 US-$) it was a bargain.

You are definitely right about metal type not lasting long with a deep impression. But I’m not going to use metall type. I’m going to use photopolymer plates.

Thanks for your reply
and all the best

Although I have been taught (by learned OF’s much older and wiser than myself) that a light, even impression is best to achieve readable copy, I have achieved “deep impression” with .025” phenolic as top sheet, and minimal underlay on the windmill… when the customer demands it. It’s their money.

I would not waste my valuable handset type on such an endeavor, but a photo deep-etched plate made of zinc, and mounted on a hardwood base to bring the type face to standard .918”. You will be pressing the soft (?) stock between two very hard surfaces with 40 tons psi.

I have been asked recently to do this on #80 linen cover, one of the hardest un-coated stocks known, and had no complaints from the customer. They wanted the “look and feel” of “real” letterpress. Phah!

The customer is always right, eh?

The thickness of packing is important in this press. Say you printing a 100 lbs cover sheet; in my case, my press takes a 80 lbs cover sheet plus 2 or three 80 lbs text to make the measure you find in the gauge. The packing would be 100lbs sheet + 80 lbs sheet + few sheets 80 text + cover sheet.

When you have more pressure on top of the platen (or in your printed sheet), that means you have to make the packing thinner.
When you have more pressure on the bottom, then you have to add packing.

How much you add or take depends on your press. Basically this is the principle for correct thickness of packing. The gauge is there for you to measure. Then, after you print a sheet, you can evaluate if the pressure is equal all across it.

Good luck