Could be a problem with the printer itself not heating the toner sufficiently when the paper rolls across the drum. Could be poor quality paper that doesn't accept the toner sufficiently. Could be any number of issues.
Does it happen often?
It shouldn't but it happens often enough. It depends on how much the printer is used, the quality of the paper, the quality of the toner itself.
What makes it transfer,
Heat, humidity, and pressure.
and is there a point at which it’s no longer transferrable?
It's less likely to happen after the toner dries (i.e. cools) but if the paper or toner is poor quality then it can still transfer even when it's dry.
“It’s less likely to happen after the toner dries (i.e. cools) but if the paper or toner is poor quality then it can still transfer even when it’s dry.”
Last thing I type for the night. This is just bnot true.
BDZ—do a little reading on it for the answers—this obot is making crap up as it goes along.
Toner is just as likely to transfer cool or hot. The powder sits on top of the paper—cold hot, whatever—if it didn’t stick by the time it came out of the printer, it’s not going to suddenly adhere to the paper as it cools.
And the paper is essentially cool within seconds of being out of the printer. It’s not metal, it’s paper.
Don’t ask this obot for any info, it lies too.
What kind of results do you usually see on the papers when that happens? Would you expect to see every page have some transferring, or just some? Would whole pages have problems, or would it be spotty on a single page?
This is sort of an aside, but is it a different process for a press? I work with newspapers and get so much ink on me and on my clothes, it’s ridiculous. I know the humidity matters but I don’t know if the offset printer uses heat or not.