Oil-based ink not drying


I printed 150 book covers 10 days ago using Graph-Chem Black Litho ink onto a heavy 540gsm uncoated colour board. The job has a heavy coverage in parts but was printed with no deep impression. When I come to spiral-bind the cover to the text pages I find the ink is not completely dry and rubs with an oily feel. The job has been stored in a stack. Any suggestions on how I might speed up the drying process would be very useful as I want to complete the binding process this week!

Hang them to dry as individual sheets?
Apply some heat - hair dryer?



Log in to reply   5 replies so far

Hang them to dry as individual sheets?

Need air flow to dry the ink, seeing that you put more ink than impression.

Try a few with heat, i know someone who would place them on cookie sheets and put them in an oven to dry, a hair dryer should work. Dick G.

Cookie sheets - bake ‘em. 5-15 min at 150 degrees.

Just stay way below “Farenheit 451”… ;)

Ink should dry overnight in nearly all cases; this situation is different. But the thermography process passes printed sheets through an oven (like a toaster oven) and uses heat to raise the glaze of the thermo powder. It will work to dry and set the ink here, too. Just don’t scorch the edges.

Although your paper may be absorbent, you still have to drive the vehicle (rubber, grease or oil) out of the ink. Only dry heat - or infrared setting (for some inks) can do this.

OR - (no kidding) lay them out in the back of a station wagon on a hot, sunny day with the widows closed. I have done this with posters. It really works.

This may sound weird, but I also recently removed ripples from the back of some old type cases - and flattened some rippled cork board this way just last week.

Next time, you may want to add some Cobalt Drier ($20 from Van Son) to your ink. It will set up quickly and dry fast - just be sure not to leave the doped-up ink on your press for too long. It will dry fast there as well, and you can only get it off using some highly volatile solvents - like acetone… It can be really rough on your rollers, too - if it dries on them.

And, for any hard-to-print-on *glossy* stock - or for overprinting other inks - or for any jobs which may go through an automated packaging process (like the food labels I imprint regularly), use Van Son’s Tough Tex line of inks. It dries quickly and stays where it’s put - it dries and bonds well.

Thank you very much for your replies – I’ll experiment with some heat.

Graph-Chem Black Litho.

This ink most likely had no drier in it. We have used this ink for many years in hand lithography, always using a drying rack. One word of caution attempting to accelerate the drying time may increase your chance for bronzing.


-Rob B