What is rabbet depth? Rabbet depth is the depth of the recess at the back of the frame that you load the contents into.
Think of the frame as a suitcase. The depth of the suitcase is the rabbet depth. When the contents sink below the level of the back of the frame – when they sink fully into the rabbet – it’s easy to hold the contents in the frame using a point driver.
However, when the contents are thicker than the depth of the rabbet, they have to be held in place using off set clips.
Rabbet depths ranging from 3/8″ to 5/8″ are common and are suitable for most art on paper with foam board backing, window mat and glass. Rabbet depths of 7/8″ to 1-1/8″ may be desirable for thicker stacks. And rabbet depths of 1-1/4″ to 2-1/2″ may be required for stretched canvas.
Note: With floater frames it’s a little different. Since floater frames are front loading frames, the rabbet depth is the depth of the recess at the front of the frame. For more on this subject see How to Measure for Floater Frames.