There are three basic, overlapping, processes in effect as linseed-oil based ink dries. Unless you're working on well absorbent paper, you'll probably need to use extra driers to help things along.
The three basic drying processes are:
Absorption: Some of the runny vehicle is absorbed by the paper. Thicker, softer papers can soak up a lot of this moisture but very smooth, hard papers can't.
Evaporation: This happens when the volatile substances in the ink (solvents, eg turpentine, white spirit and the like) evaporates.
Oxidisation: Over the course of around 24 hours, the ink takes oxygen from the air to complete the drying process.
Heating is an obvious way to speed things up (a portable heater is very useful) but proprietary driers will give you an ink that can be relied upon to dry hard overnight (almost always!).
These driers introduce a fourth process, a chemical reaction called polymerisation. Driers are nasty, and one of the most important printing products to keep away from children. But they do a very good job at drying inks and only a tiny amount is required.
You can buy these driers in two forms, liquid or paste. In both cases they shouldn't form more than about 2.5% of your mixed ink, although in very cold situations (eg garden sheds in January) you might consider an extra 1%.
We recommend Lawrences Cobalt Driers for linseed-oil based inks.
Mix well into ink on an inking slab (not the ink disc on your press). Wearing suitable gloves is advisable and, of course, wash your hands afterwards.
Ink in tubes is usually made runnier than that in tins, but with tubes you don't have to fight the skinning problem (see: ‘Skin Deep’ in Where Can I Find... Inks & Hand Rollers).
You can – and some books recommend – putting ink from tubes onto some clean (unprinted) newsprint so that it can suck up some of the vehicle. You can transfer it to the press after about 10 minutes (turn the newsprint over and you'll see the absorbed vehicle).
You Might Also Like...