Upon watching some youtube videos recently, I realized that I use a lot more medium than most people in my first pass of painting. If I add anymore medium in subsequent layers, I will probably exceed the manufacturers recommended ratio of medium to paint. I'm not sure if it matters, but to be specific, I am using Gamblin Solvent Free Gel which the manufacturer says should be treated as 100% fat.
This leads to my question -- The medium I'm using dries quite quickly (3-4 days). Does the fat over lean rule apply if previous layers are already dry? Or does it only apply to wet layers over wet layers which are drying simultaneously at different rates?