Most of the major frame companies will have a series of float frames. You need to determine how much depth you want with your canvas. Even then
you still may have to use spacers to get it just right.
You also will have to determine just how much distance you want from the edge of the canvas to the inside of the floater.
Examples I have used,
Larson Silhouette (wonderful frame, black rounded top but very expensive)
Studio has several versions of a floater that is very close to Larson's silhouette, but it is cheaper
Roma, wonderful floaters, but by far the most expensive of any I have listed
Omega, makes a an entire series of float frames.
All of these are brands of frames and can only be purchased by a framer. I would recommend finding a local frame shop that carries a wide variety of
frames and then ask them to see some corner samples.
Also unless you have exact sizes and even then it can be tough, it is very hard to get a mail order float frame to fit.
Paul Caldwell