C&P: Ink intensity reduces slowly as more impressions are made.
Hi everyone,
Currently my C&P (basic ink disk, no fountain) prints like a champ, but I am finding it quite challenge to maintain consistent color intensity on my prints.
Usually I’ll ink up, run the press until ink is uniformly spread on the disk and rollers. .
First 5-10 prints might be a little smudgy, but this eventually normalizes into nice, crisp prints, with good color intensity.
However, I find that color intensity gradually decreases as I approach 50 impressions (maybe even less impressions, if the artwork area is large), and soon I find that I’ll have to do a double print to maintain the color intensity of the initial print. I find it quite strange, because this happens even if I am printing a small name card, with a tiny bit of text. Why does the ink color intensity fade, when the amount of ink impressed onto the paper is so little per time? Does the simple act of running the machine (even off impression) somehow “dry up” the ink?
I will then usually stop the machine and re-ink the plate. Usually I leave the chase in place when I do this (to prevent any unintentional registration issues). I will then have to run the machine (off impression) for another minute or so (to spread the new ink evenly on the ink disc / rollers). Because the printing plates are continuously being inked during this time, they also become being “smudgy” again, and I’ll have to print another 5-10 impressions to get things “crisp” again.
This leads to multiple issues:
- Prints are inconsistent in color intensity (Starts off strong, drops gradually, and then back to strong again)
- Time taken to stop work, re-ink, and test print again.
Is it normal that my color intensity starts to fade to an unacceptable level after 50 or prints? First 10 prints are usually beautiful, crisp, with good intensity.
If this is not normal, I suspect perhaps my roller heights are not ideal. They “seem” correct, based on the gauge dipstick method, but I feel I could possibly raise them slightly, which might allow me to use more ink in the ink plate, without the effects of over-inking.
Appreciate any advice!
Thank you.
Sprocketty
Sounds a bit like you are over inking initially (first 5-10 impressions). Depending on the size of your form, I don’t think it unusual to get a lighter impression after 50. Add tiny amounts of ink at the 10 o’clock position of the ink table every so often (maybe 10-20 impressions? it depends on form size) it will usually be spread out by the time the ink table gets around to form area of the rollers.
If you completely re-ink the press, take the chase out or you risk seriously over inking the form. The press is designed to put the chase back in the same place.
is the ink disk turning as the press cycles?
A technique I have used on longer runs is to roll a fairly heavy coat of ink out on a slab with a brayer, then ink up the press lightly — enough to achieve the color you want. You can now replenish the ink on the ink disc from the brayer, every 10-20 impressions, without creating blobs that must be evened out, and without the necessity of removing the form from the press for re-inking. I usually add the ink from the brayer on center so it gets evened out quickly but it is not enough to be very visible on the inked print. You will need to replenish the ink on the slab occasionally to maintain uniformity on the press, but that doesn’t involve changing anything on the press.
Bob
To get the chase in the same place every time when I put it in the press, I am in the habit of pushing it all the way to the left every time.
Another source of misregister is if you have the quoins on the same sides of the form the gauge pins on the platen are on, and then you unlock or tighten the form for some reason. Always have solid furniture on the gauge pin (guide) sides, and the quoins on the opposite sides.
If you do these things, you shouldn’t have any register problems if you take the form out of the press, and then put it back in.
I place my ink near the rim at about the 7 o’clock position every 20 or so impressions (depending on coverage). By the time the ink has worked its way around the disk (the rollers generally won’t pick it up at the top of the disk), it is thoroughly worked and reduces any change of hue.
The constant addition of ink in small amounts will yield more consistent results. For long runs, a fountain is indispensable, though presents different operating challenges.
I don’t usually add the ink at the 10’oclock position if I’m running the press without the fountain. I usually add it to the bottom edge of the disc, just to the left of the form. This way it is allowed to even out as it works all the way around.
You’re going to have to do this like every 25 impressions if you’re seeing it lighten at 50- so that the ink remains consistent. If you’re adding in after you see the problem occur, you’re repairing after the consistency has already shifted. If you maintain consistency there’s no evening out to occur.
I print with a fountain on my C&P model N, so this is not an issue for me as much as for you, but I sometimes move the fountain up out of the way when printing smaller/shorter runs as it’s easier to not bother loading/cleaning it.
Good luck.
I think AdlibPress has the correct approach. The base of the Golding Pearl #1 for example has a slot on the right hand side for a plate on which the ink is rolled out. I have seen pictures of some other presses with a plate on the right.
On small presses such as the #1 the turn the disk with your left hand while running the brayer across to distribute the ink with your right.
Don’t just check your prints when running, look at the ink disk. You will be able to see visually the range of orange peel effect to get a consistent print. Also listen to your ink as the rollers run across the disc, that will also tell you when you have over inked or running out.
Getting 20 consistent prints from one charge of ink is about your max. Go find somebody running a Heidelberg and ask them to turn the duct off when it is printing with the right amount of ink and see how long you get a consistent print.
I second all above.
I do find that when I mix to the pantone guide things are a little light. I always mix a tad (not too much) bit darker to get the right color.
I find about 50 impressions is the max I can get before needing to re-ink. I either scrape a thin bit at 7’o clock and let it work around, to take the chase out (if it has intricate areas I always take it out to avoid filling in). I never had a problem with alignment when I put the chase back. They were designed for the chase to be removed before re-inking I think.
One tip: when you’re starting your press run and you get that first perfect print - keep it in front of you on your delivery board right next to where you are stacking the prints so as you pull prints you can quickly compare when it is starting to get light or when something changes. Doing this has ensured I get a lot more consistency in the prints and I can add inks in small dosages every 25-35 prints or so and ensure a nice even run without every stopping the press.
Regarding your small forms - it’s probably ink starvation on the rollers. Even when I’m printing something small I find every 5-10 prints or so I let the press ink twice to ensure better coverage.
I love the idea of the brayer, but I hate cleaning anything extra haha!
One idea on the small forms it to lock them up high in the center (left to right) of the chase — when they are in the center of the chase they remove ink typically from the center of the ink disc and that area isn’t as readily replenished as the edges by the rollers running over the disc. Left to right centering puts less stress on the platen but up-and-down isn’t quite as critical as long as you don’t go above the platen adjusting bolts.
Bob
Thank you so much for the tips / advice. I feel comforted that it is not unusual for prints to getting lighter after 20 or so impressions. I will start “topping up” ink in smaller amounts, more frequently from now.
Chase removal / re-insertion doesn’t usually mess up registration for me, as long as i make sure the chase is flush to the side of the press (my chase is very slightly smaller than the containing area, hence there is a chance it could be shifted left / right). Sometimes I forget to do this though! If I forget (ie. Chase not flush), I don’t usually dare to take the chase out…
Ink starvation is also an issue sometimes. For a long time I thought there was something wrong with my press! I had originally thought that triple rollers (C&P 10x15) would be enough to prevent any ink starvation issues. I guess I was wrong. Looking up other discussion threads, I’ve learnt that I can a) rotate form to minimize this effect; or b) ink twice every 5-10 prints to help even out coverage.
The challenge is that the “lightening” is sometimes very gradual, so I don’t notice it until it is too late! Hence, as advised, I will start keeping the first print always in clear view, so I can compare color intensity at every impression.
Thank you again!