Mystery inking (?) Issue!
So I’m having this weird speckling problem on some prints. Printing on a new style C&P. I’ve tried a bunch of things to troubleshoot to no avail. I tried changing order of both trucks and rollers. So I don’t think it’s that. It’s not plates or inks since it happens on different plates with different inks. The ink disc is above the rails so it’s not that. It’s not pressure because this is one of those job shops that uses deep impression (it makes me cringe for the equipment but it’s my job). I can vaguely compensate by double inking (which keeps the pattern actually but more dispersed so looks like more coverage) or packing behind the block/plate but that doesn’t always work to get rid of it and then it’s not crisp.
The one thing I’ve been considering is if it may be micropitting on the ink disk but it doesn’t look any worse than other presses I’ve worked on. I’m nervous to resurface it because that’s not reversible and I feel unsure that’s actually the problem. Anyone have any thoughts or have seen this?
It’s not letting me attach images even though I removed spaces and symbols. Will try again later from a computer rather than phone.
Sounds at first thought like a roller issue, if you can post the images that should help figure it out
Are you describing small voids in the print, like on bold type or art?
Are you using a textured stock ? Many years ago I encountered problems that came from dust and loose fibres coming from the stock, you could try a coated stock to see if you get the same problems.
I’d agree with Mr. Hemmings. That sounds like it could be picking. What stock are you printing on? Soft, pillowy papers like Lettra are really bad about picking.
Another set of questions would be what kind of coverage are you printing and what size C&P? If you’re trying to print any large solids on a platen press you’re going to get some speckling. It’s just the nature of the machine. They’re not really suited to heavy coverage printing. This is especially true on the 8x12 and smaller platens.
I agree that photos would help, if you can get BP to cooperate.
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Michael Hurley
Titivilus Press
Memphis, TN
My first instinct is to concur with Frank and Michael, and suggest it could be picking.
If it is a cumulative problem, the paper could be letting go of some fibers and then these fibers can remain on the rollers, on the ink disc, on the plate, etc- and create problems for you. They may not even be that noticeable.
One remedy for this is slightly softer ink, which if you aren’t already aware of how to modify the ink- you would just mix a little bit of tack reducer into some ink before you print. Be pretty sparing with it as it’ll make the ink runny if you add too much, but just the right amount can overcome picking as the ink will not be as sticky. This helps with release on larger areas of solid, as well.
(Sometimes with cylinder presses- vandercooks and the like- looser ink creates a noticeable ‘bubble’ effect, where the ink is ‘pushed’ by the squeeze of higher pressure as the cylinder travels along rotating the paper against the form. You’re on a platen so it isn’t as likely to be a problem but can still show up if you over-loosen your ink, as the rollers will possibly slur it a little.)
It could be that your ink is too firm for the type of paper you’re printing on. If you are printing on Lettra, I would imagine a lot of your larger solids are giving you problems. I would recommend making some sort of rider roller and also to cut your ink a bit with transparent white or mixing varnish to that it will lay down onto the stock better. You may also need to make ready the INTERIOR of your solids, as the image edge will tend to take the greatest impressional load (a typical problem with platens.
If your runs are long(er) a fountain may be useful in keeping a consistent ink flow.
Michael Seitz
Missoula MT
I agree with these posts but still need more info. A picture or two would be very helpful.
It really does not want me to load images. I made an album here and happy to add on. Inking issues c&p: https://imgur.com/a/x1eu3AU And for some reason my morning brain had me write platen instead of inking disc on the inage captions so please ignore that.
As for your helpful comments: Yes, c&ps were made to do beautiful type and don’t like large surface areas but this is my job and someone who doesn’t print much does the designs. That said, it often prints the large coverage areas really well. Rollers are in great shape in my opinion. About a year old from Ramco (and I love Ramco) and well maintained (never left on platen or flat surface, kept in darkness when not printing and cleaned with proper washes etc). The lettra itself I am not thinking is not as much the issue (well besides the fact that deep impressions and this sort of paper are destroying the machines :( but again, this is my job someone pays me to just print and not deal with customers…) because with the pressure compresses the paper that it becomes no longer fluffy. It could be picking but my gut says it isn’t because it happens in the very first print where it won’t have had time to pick up fibers and the press is covered immediately after cleaning everyday… That said, I think Michael Seitz is probably right with the combination of this paper and some of the inks which I can test next time it happens with another paper and/or cleaning the press and adding transparent (and changing nothing else). It’s hard enough for me to get my boss to get me more ink knives so a fountain is pretty much out of the question. I guess I’m kind of wondering if the surface of the inking disk could be contributing to the problem or if it really is a viscosity issue. Hopefully the pics help
It won’t let me fix the image caption where I said platen when I meant inking disc. I swear I know what press parts are and can use the internet ^_^
It looks more like the plate is rejecting the ink.
Oh that’s an interesting theory… That seems certainly possible. It looks like how water pills on oil. Do you know why or have any solution to that? I don’t know the effect of alcohol on photopolymer..
Boxcar Press has some helpful tips regarding plate cleaners.
Don’t use alcohol is one of them. Personally, I only use copper engravings, but I have seen this effect when I mixed up press wash and type wash by mistake. That was decades ago, and now all bottles in my shop are clearly marked. Your pictures are really good. Colophon is right. I would ask my graphics supplier their recommendation for a photopolymer plate cleaner.
Hello all,
This looks to be a classic case of “piling”. This is or can be caused by one of or in some cases several things. But to explain it easiest is to say the ink is not flowing out. It can be too cold, the ink can be too stiff. Yes it could be incompatibility with ink and plate but this can be easily and quickly proven out with a plate cleaner, and unless you are doing some process very consistently that would allow it to effect many colors…I doubt. The quickest remedy is the cut the ink with VanSon smooth with. get the ink viscosity between peanut butter and mayonnaise. Some rubber base inks are quite stiff and require cutting slightly. Hope helpful,
-Clay
Soory auto correct-
VanSon smooth-lith.
Two UK printers have had a long look at your ‘dapple’ effect in the images you sent.
We both agree that it doesn’t look like picking, and if it were we use tiny amounts of petroleum jelly as a tack reducer, and also a trace more driers to balance that. On the other hand we do definitely think its something to do with the ink or maybe an ink and pressure combination. It might just be that the ink is too runny and we would add a little talc to stiffen it up a shade, to give it more ‘body’, Baby bum powder does nicely. Could it be that another makers ink might be better, remember ink in tins is usually stiffer than that in tubes. Remember also that ink sold for commercial use nowadays usually isn’t quite ‘finished’, and depends on a final milling on your press in your multi-roller pyramid, but the ink makers don’t tell you that. i.e. whats made for a fast litho press aint ideal for a treadle platen.
I sometimes had similar problems and have solved most of them by mixing in some ‘Gelee’, that I bought from Drucken und Lernen in Germany.
http://www.drucken-und-lernen.de/Detailview.92.0.html?&tx_ttproducts_pi1...
It slightly changes the viscosity of the ink and creates a smoother print, without speckles.
Problem solved! It was (drumrolll)… Ink being too loose! thanks everyone and especially those of you who insisted on that.
What threw me off was the printer before me insisted that the only way to solve it was to mix more and more trans white. AND I was using mostly his premixed inks. So the different inks didn’t work because they all were too loose. I’m used to much stiffer inks but not used to so much pressure or lettra so assumed that was part of the deal (silly me). I asked for mag carb (my preferred stiffiner, but I’m excited about trying the other ones suggested) months ago since there was only stinky medicated foot powder (yes, it will do the job but, why?).
I ran into the problem on a purple print this morning and tried cleaning plate, adding pressure, almost no pressure (hand printing), and adding tons of trans white over an hour (made it worse of course). I also tried cleaning the press again in case it was from a cleaner or solvent. Finally I decided to go grab the stiffest ink we have (of course the black ink) and voila! Problem solved. I took pictures for posterity (please excuse the cultural appropriation, not my design) http://imgur.com/a/oJ09IkX thanks so much everyone!