Ink/impression on SP-20

I’m having some issues with a print I’m working on today. It’s a long form (photopolymer) – approx 17” – that I’m running vertically.

I’m using photopolymer on a solid wood base that’s shimmed with chipboard up to type high. Printing on Lettra 110 with black ink. The initial couple of lines are very heavy, inkwise as well as impression, but then within an inch or two the ink becomes more consistent, although not dark enough. I tried rotating the plate and running it horizontal, but I just got very hard impression and overinking on the leading edges as well as the opposite edge of the type. I’ve adjusted my rollers to type high as well. I have a rider roller for the press, but I’ve never used it and am not sure how to attach it, in case that might help the situation.

In case the attached images aren’t large enough, here are full-size jpgs:


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Rider roller? A picture of the press setup would help in understanding your problem. Using inaccurate material like chip board should be avoided, and a wood base is almost by definition inaccurate.


I think I’ve evened out my issue by A) going back to horizontal and B) using some tall and narrow wood type I’s as bearers.

The wood base is actually MDF, so I think it’s fairly consistent in thickness. What do you typically use to shim up a base that’s not high enough?

I wonder about the “rider roller” as well. Are you talking about the distribution roll which bridges the gap between the form rollers? This is a necessary part of the ink distribution system on a Vandercook. You would not get good ink distribution from the ink drum to the lead roller without it.

John Henry

No, I have an addition small metal roller that I was assuming was an add-on rider roller. I’ve no idea where it would fit in the train, though.

Pictures—imagination goes only so far. MDF is not accurate in printing needs. Any wood product will absorb moisture, can be crushed, may warp. etc. Accurate bases are available so why fight the variables? Much frustration can be avoided by investing in the right options.


MDF and chipboard as a plate base will compress even if it isn’t untrue in dimension when not under pressure. You want a rock solid and level footing for your plates. Order a metal base or have one made and you will not regret it!


I agree with Fritz and DGM. The dimensional tolerance for all thicknesses of MDF is +/-.005”, which is significant. (Source: page 7)

If the extra rider is identical to the one in use, it may just be a spare part.

I have a 9x12 boxcar base but my plate was too big, so I tried to home brew it. Clearly not the best choice.

I’ll have to post a pic of this extra roller on Monday. It’s not the same as the small distributor roller.

In a few instances in the past when I have had a plate that was just a little too big, I’ve used some metal furniture turned on its side with some metal strip material underneath to extend the base by a little bit. Just another bodge, but at least it let me get most of my plate on a proper plate base and nobody spotted any difference in the printing.

But imagine what you could do with TWO 9x12 bases. We printed an LP jacket today that used a lockup with 9x12 bases for the front and back art, and a 4.5x7.5 base in the center for the spine text. It did the trick!


Yes, I’d love to get another base…just need to save some money.

Here’s a picture of this spare roller I have. It seems a little wide to attach anywhere on the SP-20. I have no idea what press it’s supposed to pair with.

I’m unable to attach it to the post, so you can see it here:

That’s a vibrator or oscillating roller for a platen press and has nothing to do with the Vandercook. But someone may really want that if it can be determined which press it fits, and dimensions are a start.


Interesting. It came with the press, so I have no idea how it got there.

The overall length is just about 26 1/2”. The roller itself is 17 7/8” long and diameter is about 1”.

I’m going to start a new post on this to see if anyone has an idea what press it’s for.