Maybe I should get a drying medium; I bought some once, years ago, but never used it and now it's all gummed up in the bottle, and brown, besides. This is why I hate to use anything other than plain, pure mineral spirits, a reliable glaze medium, and a dependable painting medium: I want the work to be up to a high archival standard. I don't want the painting to darken or change color.
More work today: touching up a few places here and there. Added some horizontal lines on the back wall, standardized the tables, taped off the extreme right side and painted the vertical frame there in preparation for doing the more detailed work in a couple of days.