leaving ink on press


I suppose this is actually an offset and not letterpress question. I run a Gestetner duplicator as well as a platen press. I run a few plates a week through the Gestetner—most of my work is letterpress or silkscreen.

90% of the time my offset jobs are in black. Cleaning the press is a nuisance and I understand it’s ok to leave rubber base ink on the press overnight. I’ve done this a few times now and it’s given me no problems.

As I said before, though, I’m only running a few plates a week and generally I run them all at the same time to facilitate striking an ink/water balance. So, I’m thinking about leaving the press permanently inked up. So long as I make sure to start the press for a few minutes each day and condition the ink in the roller train, am I going to run into problems come print time if the press has been sitting inked for 4 or 5 days without use?



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I used to do exactly that with an AB Dick 385 in daily use, using VS Electrostatic Black, perhaps a modified rubber base ink: 9M impressions on newsprint each day. Washed up once a week and might have gone just a bit longer if it wasn’t for the paper fibers migrating up into the ink train.
No ink will stay open on the press indefinitely though. You must work the ink and wash up when conditions—tack, emulsification, dust, etc.—demand it.

Bad for your rollers! I clean my press after each session, and if problems arise I will stop printing and do a light cleanup in the middle of a job.
- Rubberbase ink may not totally dry but it will harden into a rubbery goo.
- The motor has to work harder to start a press when the rollers are effectively glued together.
- In offset printing the fountain solution migrates into the ink train, degrading the ink and causing toning and other problems.

If you clean the press after each session you will have fewer problems and your equipment will live longer.

Just my opinion.

I’ve got to side with Sharecropper on this one. It’s always better to leave your press clean at the end of the day, especially if it’s going to sit for a few days. I know it’s a pain, but it’s a better practice.

You will find that your ink/ water balance will stay a lot more consistent, you’ll have fewer problems with lint and hickies, and your overall printing quality will be much better.

Of course if you aren’t concerned with quality, then by all means leave ink on your press for a week or so….. it is easier and cheaper to do so.

What you might consider doing is to clean the rollers, but put a piece of plastic wrap in tight contact with the ink in you fountain, keeping that ink ready for use.

There are a lot of shops with duplicators like your which just wash when absolutely required, but as the sly cat says, quality will suffer. A once-a-week washup doesn’t seem to be too much of a burden.

Great! Thanks for the advice everyone. This was the push I need to clean the press after every use. I’m hoping to do more fun work in different colours anyways, so cleaning will be necessary then, but for the time being I will keep the press cleaned up.