I've had a frustrating couple of days in letterpress world. You might remember these calling cards I printed a few weeks ago, which came out decently but overall I wasn't thrilled with the level of impression the paper took. So, I decided to order in some 134# Aqua Cranes Palette paper, since the 100% cotton is supposed to do really nicely with letterpress. It really is tasty paper, and I was excited to try it out. So on Friday I prepped my Pilot with the same calling card plate and mixed a nice deep green color. I pretty much ran into every problem across the board: not enough impression, uneven inking, un-crisp printing, too much ink, not enough ink, etc. It was just one of those days. So, I decided to just pretend it didn't happen and instead try again on my big 8 x 12 tonight.
Unfortunately, things didn't go much better. I'll start with Problem #1: Uneven Print, and excuse the crap photo but I'm too tired to do any better:
See how the print is heavier on either side, like the "www" and "m"s in "com"? It gets lighter/crisper in the middle, but the edges just look really...squishy. I thought maybe it was just an uneven impression problem, so I spent a long time doing some serious makeready - cutting out individual letters from packing to try and compensate. The weird thing is, this exact same problem was happening in the exact same places on the plate when I tried the print on my Pilot at home. Question: Could this mean that the plate itself is uneven?
As soon as it started to look okay, I ran into Problem #2: Uneven Inking. Basically it seemed like a lot more ink was being laid down on one side of the plate than the other. There's a circular graphic at the top of the card, and it was really apparent that one side of the circle was printing more heavily than the other. Looking at the back of the cards, it didn't seem like the impression itself was uneven (indicating uneven platen pressure), so I thought it must have been the roller just laying down more ink on one side. I tried taping up the rails to raise the rollers on just the bottom of the chase, which only sort of worked. Since I don't have a picture, I'll do my best approximation via Illustrator:
Question: Is it common for uneven inking to occur vertically like this? How can I compensate for this?
This brings me to Problem #3: Un-Crisp Printing. Once again, I'll do my best to illustrate this problem without a photo. The left side is what the graphic should look like, and the right side is how it has been coming out:
As you can see, there are some fine details in the flowers that should remain unprinted. Instead, the flowers are completely filling in with ink. I noticed that the problem got worse the longer I printed, so I'm wondering if maybe the ink was heating up and getting too squishy. I thought maybe the problem was simply too much ink, but when I removed some from the press all I got was a mottled print - incomplete coverage indicating too little ink but the lines were STILL filling in. The only thing I can think here is that I need to dry up the ink a little. I ordered some drier from Braden Sutphin the other day and will give it a try - but does anyone know if I'm on the right track here? I'm pretty out of ideas, and I know that a crisp print CAN happen along with a deep impression.
Question: Is ink consistency to blame when ink amount has been ruled out and fine details are still filling in?
::sigh::
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your rollers are not set correctly!
ReplyDeletehi "it's fancy" - thanks for the comment! which problem are you referring to, and what do you mean by "not set correctly"?
ReplyDeleteThe first thing to do is make sure the basics are set correctly: platen adjustment and roller height. Even if you made adjustments that seemed correct previously, I've found that it's easy to miss something and that another "final" adjustment is needed once printing actually begins.
ReplyDeleteI don't mean that these things need to be adjusted every run. But on both my original 8x12 and my current 10x15, after I had restored them I set them up, adjusting the platens and rollers. But in each case, once I began printing I found I needed to make slight adjustment to bring everything to a final place. This is probably because, with a brand new press, using the standard adjustment methods would likely be enough. But on old presses there is wear, and the consequences of that wear may not show up until doing an actual print run. The additional adjustments were minor, some very tiny tweaking of the platen bolts and removing a couple layers of tape from the rails.
So if you have never adjusted the platens or rollers using one of the standard methods, I'd do that first, i.e. go back to square One. If you have done that, then go back now and double check those adjustments. One thing to remember is that measurements using gauges are OK, but it's the end result that counts. For example, you may get a proper length "stripe" on a roller gauge, but on your press that may not work and will only provide a starting point for a final adjustment.
When I was adjusting the roller height on my 10x15 I found that a gauge was helpful as a starting point but that afterwards I still had to use some trial and error, removing strips of tape from the rails one at a time, until I got to a point where I was getting good inking. And don't forget that a larger form will print differently than a smaller one because of the difference in impressional strength over the surface of the platen. I used a midsized form as a test during "tweaking" in order to fall somewhere in the middle and allow the most latitude.
Another thing to remember is that makeready is not a substitute for having the press set up correctly. It serves more of a purpose compensating for worn type or warped wooden bases on cuts, or plates that are not 100% accurate, etc. But good, effective makeready requires a good foundation to start with and that foundation it a properly adjusted platen and rollers. This can take a while and be tedius, but will pay for itself since you will be able to troubleshoot the inevitable problems more quickly and effectively.
I won't say anything about the specific issues you had because I don't know whether you need to revisit your basic setup. I think It's Fancy was referring to the fill-in on the print of the flower. That would seem to indicate the rollers are set too low. But again, there are other issues you're having and I'd check your basic settings, which would include roller height, first.
BTW: Don't forget about underlays in terms of makeready. You can drop a sheet of paper or two behind the chase to raise the form a bit for increased roller contact or impression if necessary.
Rich
Front Room Press
Milford, NJ
http://frontroompress.com
http://frontroompress.blogspot.com
I was referring to the fill in on the flower and the thicker edges on the printed text. I have found that I sometimes need to adjust my rollers depending on how much text I am printing. If it is very little text I make sure that my rollers just kiss the plate ad they roll across. That way you are not inking the sides of the letter forms making them appear bold when printing with and impression.
ReplyDelete