Heat the linseed oil in a double-boiler and mix it with approximately 2 percent beeswax. When the ingredients have been thoroughly mixed, the oil should cool for one day in an airless container.
Set up your materials and put on your safety equipment. Remember to wear your mask, because pigments can easily become airborne and some are highly toxic.
Mix the pigment with the linseed oil mixture you prepared the day before. Do this on the grinding surface, grinding the pigment with the oil in a circular motion. Note that the final mixture will be 60 percent to 80 percent pigment. The exact proportions will depend on the type of pigment and oil you're using.
Continue to mash the pigment and oil, adding more pigment and oil as necessary. Grind the mixture into a smooth paste.
Use a spatula to gather the paint when it's finished and place it in an airtight container for storage.