Technique of oil painting and preservation of paintings

[Konstantin]

Very interesting, thanks for the experience. Paints a surprising number. All did not pereprobuesh.
Paul then said that if you do not wait until fully dry (a dry white for decades), then two weeks later something is black. I do not have such experience, often without waiting for 100%dry, some pictures for many years, but did not darken. What experiences have others?