bleed through with Heidelberg

Hello everyone,

I became the owner of a Heidelberg 10x15 over the summer. I’ve been printing with it steadily, learning more each time. I’ve been running into a bit of trouble, though, and I was hoping someone could offer advice.

When I print with dark red ink – Van Son, rubber base – I get bleed through to the reverse side of the paper – Crane Lettra 110# – even if I back the impression off. I’ve tried to ink very, very lightly (which wouldn’t work in the long run because then the color is more like fuchsia), but I still get bleed through. The press is feeding well, although it will skip every so often – but it doesn’t appear that the bleed through only happens after the tympan has been inked. It can happen in the first impression or anywhere along the way, if that makes sense.

I do not have this trouble with this color when I use my Vandercook SP-15 with the same paper and photopolymer plates. In fact, with the SP-15 I can ink more heavily without worry of bleed through.

Thoughts? Your advice would be greatly appreciated!

Thanks in advance,

Lynn Russell +++ Satsuma Press

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sounds like your trip needs adjusting, when the feeder doesn’t pick up, the press should shut off, maybe you need to take out smaller piles of paper from the delivery, on heavy card stock i usually take out every fifty or so and stand them on end, this helps a lot. good luck dick g.

Are you absoluteky certain this is bleed through?
Sounds more to me to be what is known in the trade as set-off; where the ink from the previously printed sheet is transferred to the back of the sheet as it drops onto the delivery pile.
I would imagine the ink would have to be very thin to actually go through a sheet of paper.
If it is set-off then either use the anti-set-off spray if it is fitted or keep the delivery pile very small.
As dickg suggested your suction trip should be set so that even the smallest fault in sheet pickup stops the machine.

Thanks for the replies.

Dick G: I will work on adjusting the trip to be more sensitive. I do have a bit of trouble with it from time to time, but even when I am not, I’m finding the ink on the back of the paper.

Bern: I’m pretty sure it is bleed through because if I stop the press with the paper still in the gripper above the delivery pile, I can see the ink even then.

I’ll keep working on this!

i agree with Bern, it sounds like you are inadvertently printing on your tympan, and that is what you see on the back of your sheet.
we have been running windmills at our shop for several years, and have used Lettra, almost exclusively for the last 3 years, and i can’t say i have ever seen the ink actually bleed through the sheet, it would be pretty tough even to make it do that on purpose, because the stock is so thick. Be sure to watch your run closely, adjust you trip as recommended above, and if you print on the tympan, stop the press and clean it with some type wash or something. You should be in good shape at that point.
Another thought is what you are using as a tympan. If you are using actual tympan sheets, they typically are made of an oiled paper, designed to be smooth and resist the ink a bit. From time to time, i have had tympan sheets that seem a little too oily, especially when they are fresh, and this can sometimes leave the sense of a bleed through on the back of the sheet, but it is actually oil from the tympan sheet marking the back where the impression has been made. This should clear as you break in the tympan a bit, but you can always tape a sheet of copy paper or what not over the tympan sheet. if you see the color you are running, than you are off setting. If you don’t see the color, just a dampening effect, so to speak, than it is likely oil or marking from the tympan.
Good luck

Thank you, Natron!

Yes, I do sometimes inadvertently print (with cursing!) on the tympan when the press fails to automatically stop. When this has happened, though, I have wiped the tympan off with press wash so I thought this would take care of it. I am using actual tympan sheets.

I use 110# Lettra not the 220# — not sure if that would make a difference to your thoughts re. the paper itself…

It sounds like the biggest thing is getting the trip to work consistently, yes?

Thanks again.

Hi Lynn,
I live in the UK.
Letterpress is in my blood having first been introduced to it at school, printing the school magazine and ending my days 50+ years later as a works director.
I have only ever used french chalk (talcum powder) to remedy an impression on the tympan. You don’t actually remove it; you just dry it with the chalk. Use one of your discarded powder puffs! There’s no need to use press wash.

Hi Bern,

In addition to press wash, I’ve also tried talcum powder for any mistaken impressions on the tympan. I’m still getting the bleed through (or whatever it may be) to the reverse!

Will keep working on this, thanks again for your help.


the only way to get ink on the back of the sheet is to print on the tympan, every time the press closes it will print on the tympan unless you throw the impression lever off. maybe you could post some pictures of what is happening. on adjusting the trip sometimes when you go from thin paper to a thick sheet you will need to adjust it, i run all kinds of stock and hardly ever have to adjust it once it is set, make sure the screen is clean at the hose connection at the trip, if this is dirty it will interfer with the trip. good luck dick g.