Drying time for any paint medium can be difficult to calculate because it is substantially effected by factors such as substrate, pigments, and drying oils.  Overall, Biobased Artist Thinner is slower than, but close to mineral spirits as far as drying time is concerned. The pigment is by far the greatest influence on drying time – umbers and siennas dry very quickly, organics are generally slower. For purposes of establishing a reference for drying time, Biobased Artist Thinner was tested by an independent lab on two very different substrates, pine wood and cement mortar.  In the pine wood substrate test, a 50/50 mix of Biobased and linseed oil was dry to touch in 60 minutes.  A 50/50 mix of mineral spirits and linseed oil also dried to the touch in 60 minutes. Biobased thinner alone with no linseed oil took 30 minutes.  To dry “through” the biobased linseed mix took 60 minutes, and the mineral spirits took 60 minutes. On a cement mortar substrate, the Biobased Thinner mix Set to Touch in 90 minutes, the same as mineral spirits, but the Dry Through took 30 minutes longer.

Here is a more detailed look at the test results….

PINE WOOD SUBSTRATE DRYING TIME IN MINUTES

CEMENT MORTAR SUBSTRATE DRYING TIME IN MINUTES