RE-USING BIOBASED ARTIST THINNER

It is common for painters to have a small container of Biobased Artist Thinner near the work area so that brushes can be rinsed between colors.  At the end of a painting session, the thinner can be left for the pigment to settle before the next painting session.  With this in mind, we decided to do a test exploring the process, with the following questions in mind:  1) Will some colors settle more quickly than others?  2) What is the time line for pigment to settle? 

The results of our test are interesting.  It appears that some colors settle more quickly than others.  In general the pigments with greater density will settle faster.  The one pigment that remained slightly dispersed in the thinner is Venice Red.  Hansa Yellow, Ultra Blue, and Treehouse White all settled leaving the thinner mostly clear.

Here is an image of all four pigments after 2 days.  Notice that there is generally good settling, with the Venice Red remaining more cloudy —

Here is the image of all four pigments after 4 days.  The Venice Red has settled more, but still not as much as the other pigments —

In conclusion, Biobased Artist Thinner is highly regarded because it breaks up resins and pigment clusters, and then evaporates leaving a secure paint film. The tests show that it can be re-used for future painting sessions, after the pigments are allowed to settle.  Pigments with less density may settle slower, but newer organic pigments will generally settle in 2-4 days.