uneven impression with boxcar base

I have a golding pearl #11 and recently got a deep relief boxcar base. I am having a bit of trouble with getting an even impression with polymer plates.

Printing a 5x7 plate. the middle is not giving me an impression.

I also tried putting a small monogram plate in the middle of the base - and that impression was fine.

but when I added another plate to the right side of the base - the monogram didn’t print at all.

(packing was minimal and not changed between plates - Tympan , one sheet pressboard and two index)

not sure where to start troubleshooting

image: 5x7 print - virtually no impression in the middle

5x7 print - virtually no impression in the middle

image: the p printed great in the center

the p printed great in the center

image: really uneven impression and the original P didn't print at all

really uneven impression and the original P didn't print at all

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First, 5x7 is a fairly large area to print with a 7x11 press, and deep impression can break the press, even with less area printing. Pearls are not made strong enough for deep impression and do not do well with large printing areas, greater than about 1/4 the chase area. Second, it appears that your image is off center of the press. For the most even impression it is necessary to center the image so that printing area is balanced at least left to right. Third, I don’t see any grippers or gauge pins, but with that size base either will cause trouble. Also, have you carefully adjusted the platen to parallel with the bed and exactly type-high on impression? Finally, photopolymer is very finiky about roller preciseness and adjustment.

Check all your parameters carefully and adjust everything to get optimum results.


Fourth, the packing is too thin, needs a few sheets of newsprint.

If i add much more packing - it kind of feels like it doesn’t want to close in print mode.

I moved the plates around a bit - and added two sheets of newsprint. seems like the top isn’t getting an impression. is this a platen adjusting issue?

it does have grippers - but they are not touching the base at all and they are compressible gauge pins

here is a better photo of the new print the left side of the print is the top side https://imgur.com/a/enlRp

image: IMG_0162.JPG


image: IMG_0163.JPG


I’ve had similar results when trying to maximize the print area on my small press (6x9.75 chase, 5x7 polymer plate). These smaller presses just don’t have the power.

You might be able to equalize the impression by adding some makeready in the areas not printing heavily enough. It is not unusual for a large form to require some tweaking of the impression in the middle. If one side is not printing well, an adjustment of the platen bolts could help the problem.

It does seem that your form may be too heavy for the press you have.

John Henry

An uneven impression like that (prints bottom, but not top) implies that the Platen needs adjusting. However, I would be very careful and back the bottom off a little before tightening the top. You want an even impression, but be careful not to overdo it. Make a small change and try again.

Don’t aim for a deep impression first, aim for a uniform light impression. Once you have that you can adjust it deeper all over, but again, small changes, and don’t stress the press. Stop as soon as it is deep enough… Or sooner if the press shows any signs of stress.

I can’t guarantee that you can get the impression you want but this is how I would try.

A note of caution about Pearls — I got two #11 Pearls for the price of one because one had been broken (the frame where the platen pivot passes through it) doing just what you are trying to do, and the other had some parts missing. I got one working “Franken-press” by swapping parts and making some minor modifications, but in the process I found that the “good” press frame had been broken in the same place and brazed back together. So be very careful about your press, or plan on replacing it sooner than you’d like.


If, as you said, “it kind of feels like it doesn’t want to close in print mode” then it is telling you not to make it close. You need to develop a “feel” for the machine, and where its limits are. As others above have suggested, the Pearl is not a deep impression press. My Pearl #3 also has a side frame broken (not by me) through the area where the platen pivot shaft passes through it, and it is braised back together.

If you want to do deep impression, please get a C&P 8 X 12, at least. In the end, you will probably be wanting a C&P 10 X 15.

Sorry to put a monkey wrench into your plans, but it is for the best.

hey guys - I’m thanks for your suggestions - we are working on adjusting the platen. my issue at the moment isn’t even the deep impression -its an impression at all!

if I put two small forms on the top and the bottom of the boxcar base (like a 1x1 polymer) they both print fine) but that 5x7 polymer just is not wanting to print even at all.

yes it would be great to have a C&P but right now this is what I have to work with.

A couple of points. You may have damaged the plate by having so little packing and tight adjustment. You can improve impression and lessen stress on the press by dampening the paper. Dampening also improves inking, especially large solids.

hey John - could you elaborate on what you mean by tight adjustment?

1. I used the lolipop to calibrate the platen so that all four corners were tight but allowed the lolipop to pass cleanly. This took a LOT of adjustments, each time I got the bottom to the correct distance I would tighten the top platen bolt and then back it off to the correct distance, at which point the bottom would immediately be too tight. I would then back off the bottom and repeat the process. Eventually it got to the point where the bottom was no longer too tight after backing off the top and then I hand tightened the locking nuts.

2. I then attempted to use the press with minimal packing (pressboard, 3 index, 2news print) which immediately created too deep of an impression on the bottom of the plate.

3. I began making micro adjustments of the platen bolts running the press without ink to verify the impression. After reaching a point where I was able to get a very faint but uniform impression I increased my packing and started getting a better impression….

BUT the press still feels like it doesn’t want to close very easily upon print impression with a larger plate. And this is not a deep bite in the paper, its a very soft minimal impression.

• Should we back the platen off more and use more packing?
• If so how should I calibrate it - since the lollipop has gotten us this far which seems to be too tight?
•Should we have used the lollipop with the packing?

The lollipop is type-high and meant to set the height of the rollers, not the platen. The platen needs to be type high plus 40 or 50 thousandths to allow for paper and packing.

There is a really nifty tool for setting the platen height (http://javacycles.com/categories/57/products/254) although I haven’t tried it yet — has anyone else? There are four magnetic disks that are .958” high that you put in the corners of the platen and then adjust till snug. One of the disks doubles as a type-high lollipop.

Or, you could use the Falstrom roller/platen gauge. Set at .968 and 350 sold. http://www.perennialdesigns.net/ ( scroll down)

Do you have smaller boxcar base ? 5x7” ?