What is the standard frame size people use for an 11x17 print with matte?
What's the size of the mat?
In our commercial printing company, one entire floor was a large, successful framing business. The guys there knew as much about matting and framing as we knew about commercial offset printing (a lot). Here's a general formula they used to determine the size of the mats for framing.
The area represented by the mat's borders alone needs to be at least the same, or more than the area of the "artwork" itself. That surprises most people. But a smaller mat looks skimpy. A properly sized mat greatly enhances the image and looks elegant.
An 11x17 image is 187 sq inches.
A mat providing 2.5 inch borders adds 5 inches to each dimension or 16x22 = 352 sq in.
Subtracting the area of the image, 187 sq. in., 352-187=165 sq inches as the area of the mat borders. Not enough.
Using 3 inch borders adds 6 inches to each dimension. So the mat is 17x23. 17x23= 408 sq inches total. Subtract the image, 408-187=221. That works nicely. 3.5 inch borders gives a frame size of 18x24. As suggested above, that's a "standard" size.
Some people like to make the bottom border a little larger than the sides and top. Personal preference on that.
Either way, 17x23 would be my minimum for the framing size. But the price of framing goes up exponentially with size.
Rich