MITRA Forum Question Details

​Dear MITRA, 

I had something unexpected happen in the studio this week, so I welome your guidance. Some background on my practice is that I have painted for decades, and use high quality artist's materials -- professional grade walnut oil-based paints with that manufacturer's walnut oil-alkyd medium, and a little high quality OMS, on a substrate of oil primer applied on a recommended brand of panel for longevity. For my current project, I am using almost all transparent colors, and have introduced a few new-to-me pigments to my palette. I use very little medium and OMS, so my pigments are definitely not underbound (nor overly oily).

I am working more rapidly than usual due to a deadline, but my initial underpainting layer (applied very thinly and in many places, wiped even thinner with a rag to achieve lighter values) had been drying for three weeks in a studio where I am currently running two dehumidifiers. This underpainting certainly seemed dry enough for a second layer, and in the first area (the face of a portrait) the first layer behaved as expected as I applied a thicker top layer (though still not "thick" per se). However, after I had been working on the hair for awhile, I wondered at first if a brown admixture was being picked up by the brush in a couple of areas, but it seemed to be glazing on since the brush didn't appear to be picking up any of the earlier pigment. I even wiped off the second coat in one small area to check, but the underpainting seemed intact, so I proceded to work. Then on the very last area where I was applying the second coat, I realized that the brush actually *was* picking up some of the earlier pigment. 

I recall seeing a scale for the multiple stages of first-layer oil drying hardness from touch dry to bone dry but I can't find it now -- I just recall that my former "bone dry" habit wasn't actually the best for longevity, and that the fingernail test (which I did find referenced in a couple of previous posts here) was a good rule of thumb (no pun intended) for when a first layer is ready for a second layer. 

It is what it is for now for me to meet this intense exhibition deadline, but does this sound like I might have longevity issues in the future with this particular work due to this situation?    

I really appreciate your help and time. 

Amy