There are many reasons that you might like to buy an Ornate picture frame. When I talk about ornate frames I am referring to swept frames that might resemble frames found in museums.
These types of frames would look pretty incongruous on a modern painting but work well when the painting is painted in a style that hints at or imitates classical landscape painting.
Family group and individual photos are also sometimes framed with ornate frames and you may like to give a certificate extra standing with one of these frames.
Ornate swept frames are not bespoke frames and cannot be cut to exacts sizes. They are manufactured in standard sizes. If your artwork is smaller than any of the standard sized frames you could get a slip fitted. Including a slip is very aesthetically pleasing addition to a swept frame.
From an aesthetic standpoint I would not think about using them to frame anything else.