Too thin or not too thin?

摘要

I have a concern with the article "Flawless Drywall Finish" by Myron R. Ferguson in Fine Homebuilding #224. It's a good article, and I agree with most of it. The concern I have is where the article talks about a skim coat. It states, "There are several ways to get to a Level 5 finish, but perhaps the simplest is to skim-coat over a Level 4 finish with watered-down joint compound."