Some frames are ready to hang as soon as your artwork is installed. However, many of our frames, such as open back frames and floater frames, are sold as just the frame face, so the artist can choose whether to purchase glazing and what kind of hardware will be best for their artwork and the space it will inhabit. Be sure to check the notes in the frame description to determine whether you'll need additional materials to complete your framing project.
Frames are sized by the size of artwork they're intended to hold. The front opening will be approximately 1/4" smaller on all sides so the artwork will be securely held in the frame. For frames with mats, the mat opening will also be approximately 1/4" smaller than the anticipated artwork size, again to ensure that the work is securely held behind the mat. This can vary from one brand to another however, so be sure to check the product description.
The final image on each frame page is a diagram of a cross section of the frame molding. You'll find the frame's inner depth, also known as the rabbet depth, indicated on that diagram. Remember to factor in the thickness of any glazing, mat, mounting board, and backing you may be using in addition to the actual artwork.