Scrap wood makes for a great guide

Getting a uniform jamb reveal when installing door and window casing is easy if you make a scribing jig like Tom Bernardís. This McMinnville, Oregon, Club member cuts a 1/4-in. rabbet in two edges of a piece of scrap lumber and trims the stock to 4 in. square. Then he sets the rabbeted edges into each of the four corners of the jamb and traces along the two edges to mark where the inside of the casing will land.
Brought to you by: <a href="">American Profile</a>