You Asked
What is whitewash? What happens when you whitewash something? — Irena, Cary, NC

Marshall Answered
Whitewash is best known for its appearance in the book Tom Sawyer. In that case, Tom was painting a fence with it. Whitewash was used as a type of white paint. People whitewashed fences, barns, houses, etc.

The advantage of whitewash is that it is something that is inexpensive and easy to make at home. It’s basically water plus lime plus salt. As such, this page describes whitewash as a very thin plaster rather than a “paint” like we use today.

Here is one set of instructions for making whitewash: How to Whitewash Walls. This is another, more involved recipe: How to Make Your Own Whitewash Paint. Either way you get a nice, white finish.