Printing ink

[pluto69]

Ink on newspapers used to rub off and make a dreadful mess, but some years ago it changed and now hardly does that at all. What did the printers do to improve things?

[Skids]

Mixed a decent adhesive in the ink, probably.

[mojobanana]

Hi Pluto,

I hope I may be of help.

It's not so much the ink, but the printing method too. There are four methods and the ones used for newspapers (e.g. high-volume) typically were letterpress and lithography. Letterpress consists of a plate which is produced manually of lots of little pieces assembled into a whole page (very time consuming) and litho used a semi-flexible aluminium plate which was exposed with films, much like a photograph, to produce the image then wrapped round a drum where ink would be applied then transferred by a blanket roller to the continuous feed of paper. The ink was waterbased and took a while to dry or 'cure' and as newspapers were printed overnight, when you got them, they were 'wet'.

As technology moved on, other printing methods became viable for these high-volume print runs. I think the Daily Mail might have been the first to move to flexography. This method uses a flexible rubber plate which is cut digitally (much quicker). The inks are solvent based and once the ink has been applied to the printing 'plate' and then to the paper, the paper goes through a curing head, which dries/cures the ink so by the time it comes out of the other side, it's completely dry.

tbc...

[mojobanana]

I believe this method is adopted more and more by newspapers because of the flexibility in producing plates and the digitalising of the whole process. Flexography technology has also moved on, so better results are obtainable with the rubber plates.

Some shorter-run newspapers (Evening standard, evening news, etc.) may even use digital print. In this, no plate is made and the image is put directly onto paper, much like your domestic inkjet or laser printer. Again, depending on the print run and technical requirements, either method could be used, but on a much larger scale!

I'm dragging this out of a 5 year old memory. Believe it or not, I have a bit of a degree in print technology! Someone please correct me if any of the details are wrong as I've never worked in printing and only have a technical understanding of the whole thing. I've tended to have been a customer of printers for retail and industrial packaging development.

hope this helps at least partially. I'll try and get more detail and come back at some point. There's probably a website out there that can explain it more eloquently than I have.

Cheers
Jo