Step1 - Varnish manufacture
Varnish is the clear liquid that is the base of any ink. Different varnishes are made for different inks, but they are all made by mixing the resins, solvents and additives (often at high temperatures) to form a homogeneous mixture. The resins react together to some extent to make larger molecules, making the varnish more viscous the longer these reactions are allowed to occur.
Step 2 - Pigment dispersal
The pigment is mixed into the varnish and then ground to break up clumps of pigment and to spread the pigment evenly through the ink.
Source: X-Polymers-E-Printing inks