Traditional Simple Methods for extending artists' colors

After years of stable prices, costs of art materials are rising just as fast as food prices. Art materials companies are reacting by introducing new lines of lower priced paints.  Regardless of the advertising, nobody should expect better or truer colors for less. 

Rather than buy a lesser grade of artists’ colors consider how you can save money by extending artists’ paints with pigments like calcium carbonate among the oldest, most stable pigments in history.  

calcium carbonate crystal

calcium carbonate crystal

The goal is to increase the quantity of artists’ oil paint with minimum decrease in quality.  As a manufacturer of oil colors I know artists’ paints contain more than enough colored pigments to extend. That means you can easily add dry pigments + oil and increase the volume of paint.  How much?  You will know.  

Perhaps you will feel a difference in texture, which you can adjust by adding more pigment or oil.  You will definitely see it immediately if you ruin color quality.  Make notes about how much extender is too much.  

  • Avoid making chunky paints because these usually do not contain enough binder.  Expect they will dry down dull and potentially crack. If you like the look consider adding cold wax medium to your mixture to keep the matte look but increase stability.
  • Overuse of extender pigments cloud transparent colors and make opaque colors more translucent.   

In general, adding extenders reduces chroma (intensity).  Like painters of the past, I recognize sometimes really intense colors are not required, especially if the painting technique includes layering and glazing.  

Muller and "figure 8"

Muller and "figure 8"

To experiment, buy a 4 fl oz jar of Whiting (calcium carbonate) and an 8 fl oz jar of refined linseed oil or refined walnut oil which are drying oils.  

The more patience you can muster for the process, the better the result.  Both pigment and oil have to be added to extend artists’ colors and linseed oil binder takes its own sweet time coating particles of pigment.  Makers of oil paints also use time, heat and pressure to accelerate the paint making process but most painters really have only time to use.  Think of this as a more meditative activity.

Start by extending artists’ grade Titanium White, which is, in my opinion, too strong for 80% of painting techniques anyway.  Extending Titanium white is a money saver and rarely a failure.  

  • Make a tint mixing artists’ grade Titanium White and your favorite color for reference.Remember while you are INCREASING the volume of your paint, you are making a mixture. Try not to make more paint than you want to use during the painting session.  
  • Place a blob of Titanium white on a glass palette and surround with a generous amount of oil.  Blend together slowly with a broad knife into a soupy mixture. 
  • Add Whiting calcium carbonate pigment slowly and keep mixing.  Mix thoroughly until you’ve increased the volume of your mixture by approx. 20%.  
  • Stop. Test the color for texture and intensity.  Match the tint to your reference.  Does your mixed white + favorite color make comparable tint?  
  • The maximum you can extend artists’ grade Titanium white paint is 50/50.  

 

extender paint compared to titanium white.  The mixture on next picture is 50/50

extender paint compared to titanium white.  The mixture on next picture is 50/50

Also consider making a small batch of extender paint. 

  • Instead of beginning with artists’ color paint, begin with a small pool of oil on a glass palette.  
  • Slowly add calcium carbonate pigment and blend with a MULLER using a “figure 8” pattern until you make a smooth paste to your preferred viscosity.  
  • Using the same slow patient mixing technique, you can make enough for a single studio session or store in a glass jar.  
  • Blot off any excess oil on top of the extender paint before using again.  For better storage, experiment with adding a bit of cold wax medium while mixing.
  • When painting with your extender paint and artists’ grade Titanium white, you can mix up to   50/50.  Use less when extending mixed whites and lead white.  

 

The modern organic colors (Phthalos, Quinacridones, Perylene, Indian Yellow) cloud more easily than the more opaque mixed metal oxides like Cadmiums.  

Consider not extending the oil colors you use for glazing.