Oils: Painting Medium Basics


A quick and dirty list of Grumbacher Oil Painting Mediums’ effects on paint.OilMeds

Speed Drying (lean additives):

Fast (approx. 4 hours):

  • Cobalt Drier – A purple liquid that comes in a bottle.  Add it sparingly to oil mediums before adding it to paint.  Adding it straight to light color paints like Titanium White will tint it blue.
  • Zec – A thick, clear gel that comes in a tube.  Add it to oil colors on the palette before applying it to your painting.

Moderate (12+ hours):

  • Alkyd Painting Medium – Thixotropic medium starts off thick but thins when stirred.  Add directly to paint on the palette.  Can be painted over in 12 hours.
  • Copal Painting Medium – Liquid painting medium that imparts hardness.  Add to paint on the palette. Best used for works other than fine art due to yellowing over time.
  • Painting Medium III – Liquid medium that speeds drying of oil colors.  Add directly to paint on the palette. Does not dry as quickly as the alkyd medium.
  • Pale Drying Oil – A thin oil that reduces paint’s consistency from the tube. Add to painting medium before adding to paint, and use sparingly.  Best used for works other than fine art due to yellowing and cracking.

Slow Drying (fat additives):

  • Oil Painting Medium II – A thin liquid that is typically used for wet-in-wet techniques.  Imparts a high gloss to dried paint.
  • Poppyseed Oil – A thin oil that is typically used for pale colors or alla prima techniques.  Not recommended for layering techniques.
  • Stand Oil – A thick oil that levels brush strokes and creates an enamel-like finish.
  • GEL – A thick gel that transparentizes paint but keeps a heavy body.

Adds Gloss:

  • Oil Painting Medium II
  • Oil Painting Medium III
  • Copal Painting Medium
  • Linseed Oil
  • Sun-thickened Linseed Oil
  • Pale Drying Oil


  • Oil Painting Medium I

Smooths Brush Strokes:

  • Sun-thickened Linseed Oil
  • Stand Oil


  • Japan Drier

Liquid Varnishes:

  • Damar Varnish – creates a high gloss finish
  • Picture Varnish – creates a satin finish
  • Matte Varnish – for pale works and smooth paintings
  • Retouch Varnish – evens out gloss and matte areas