Measurement guide
Measure the space the package actually fits.
A frame's advertised size may not match its usable rabbet exactly. Measure the recess that holds the glazing, mat, artwork, and backing before cutting anything.
What to measure
- Lay the empty frame face-down on a protected surface.
- Measure the horizontal distance between the inner rabbet walls at the back.
- Measure the vertical distance the same way.
- Measure twice at different points; use the smaller value if the frame is not square.
- Subtract a small fitting allowance appropriate to your materials and shop practice. The result is the finished package width and height to enter in RabbetReady.
Do not confuse two openings
The rabbet opening holds the package at the back. The smaller sight opening is what remains visible from the front. RabbetReady asks for the finished package dimensions after fitting allowance, not the visible opening or raw rabbet measurement.
Manufacturer tolerances, wood movement, corner joining and finish buildup can alter real dimensions. Never cut an entire batch from a catalog size alone.