What is the ideal angle for a standard miter cut on a picture frame corner?

The ideal angle for a standard miter cut on a picture frame corner is 45 degrees. This angle allows the two pieces of the frame to come together at the corners, forming a neat and professional-looking joint. A 45-degree angle is half of a straight angle (90 degrees), which is crucial for creating a square corner when the two mitered edges meet.

Using a 45-degree angle ensures that the frame maintains its shape and that all sides are equal in length, which is important for aesthetic appeal and structural integrity. This is a widely accepted practice in framing, as it allows for even distribution of stresses in the joints and helps in achieving a perfect fit.

The other angles listed do not provide the same functionality; for instance, a 30-degree cut would create a much larger corner, which is not suitable for standard picture frames, while 90 degrees is appropriate for butt joints but not for mitered corners. Likewise, a 75-degree cut would not form a proper corner joint for frames, leading to misalignment. Thus, 45 degrees is the standard for achieving the desired appearance and strength in picture frame construction.