Concepts of Painting

Mediums

Too many mediums exist and are constantly created to list in entirety. The best advice is to read descriptions from manufacturers on intended use, drying times, effects, etc. What follows are some of the more basic descriptions of a few mediums. 

  • Clove oil: Nondrying oil. Film stays wet for weeks. Dries weak and spongy.
  • Stand oil: Vacuum thickened linseed oil. Levels paint. Very thick.
  • Sun-thickened oil: Same viscosity as stand, but thickened with oxygen).   
  • Black oil: Very fast drying. Linseed oil with lead. Will not darken. 
  • Maroger, NeoMegilp, Liquin: Leveling gel mediums. Can add some transparency.
  • Alla prima medium: Variations of Turpentine, Damar, and Stand oil Mixture.  Michael Harding has many subtle variations, such as PM 5.  An in-studio mixture 1 pt. Stand, 1 pt. Damar Varnish, 5 pt. Thinner. Dries quickly to gloss. 

Simple oils (and a few resins) have been proven in the test of time. For those wishing to work with only traditional oils, here is some information ranking them on strength, drying speed, and tendency to yellow. 

Linseed Oil (cold pressed)
  • Viscosity: low to medium
  • Drying Time: fast 
  • Color: pale straw to deep yellow
  • Notes: Yellowing and embrittlement (age, exposure to light, cold temps); darkens when stored in the dark. Pale oil may revert to darker yellow while aging.

  • Common Uses: vehicle for paint suspension, modification of viscosity. 
Linseed Oil (alkali refined)
  • Viscosity: low to medium
  • Drying Time: fast 
  • Color: pale straw to deep yellow
  • Notes: Refining process increases the potential for embrittlement. Addition of alkali lowers the acid content which reduces tendency to yellow. 
  • Common Uses: vehicle for paint suspension, modification of viscosity. 
Poppy Oil
  • Viscosity: low to medium
  • Drying Time: slow 
  • Color: light yellow
  • Notes: Slow-drying (additives used in paints). Should be used sparingly. Creates a less firm, possibly spongy paint film, susceptible to cracking. Less linolenic acid = less yellow and weaker. 
  • Common Uses: vehicle for light pigments, modification of viscosity/drying time. 
Walnut Oil
  • Viscosity: low to medium
  • Drying Time: slow 
  • Color: very pale
  • Notes: Non-yellowing oil. Can turn rancid and spoil if not refrigerated. Paint film is durable, though not as durable as linseed oil.    
  • Common Uses: vehicle for paint suspension, modification of viscosity/drying time. 
Safflower Oil
  • Viscosity: low to medium
  • Drying Time: slow 
  • Color: light yellow
  • Notes: Relatively slow-drying (additives used in paint). Yellows less than linseed. Gets brittle faster than linseed.     
  • Common Uses: vehicle for light pigments.