Hey, Sam,
You've pointed out the advisability of using a synthetic rigger brush for thin vertical lines. Do you dilute the paint in any way when painting the thin lines? I don't use turps or mineral spirits and it doesn't seem to be working with linseed oil the way it used to in the past. Are some brands of brushes particulary recommended more than others?
I can't thank you enough for this awesome SKOOL.
Carol