Here's a very tiny oil painting I completed recently: "Man, Apple, Loch and Key." Got ahold of some carpentry wood scraps recently, and have been having fun with them. The first image shows the actual size of the painting. The coin is an American penny.
It was too small to sign so I put my initials, TB on his shirt. You can barely see the signature initials in the image, above, in the lower right corner.