For some printmakers this is the reason to make their own inks. All in all enough reason for us to start a survey abour commercially available printing inks. While the comparison was is progress, many differences showed between the inks. The viscosity is an important property of ink and depends upon the time used for boiling the linseed oil. This process is called polymerisation.
Viscosity increases with the length of the boiling time.
In general one can say that wiping off a plate is easier with buttery ink than with stringy ink. The latter leaves some marks. This however not true for every ink. There are inks that are stringy but yet easy to wipe off. This might be accomplished with some additions.