Works on paper
With a few exceptions, all of my works on paper are made on 100lb Bristol vellum, a good thickness card stock.
I usually reserve a blank part around the image. During the framing, you will be able to Choose a mat which slightly overlaps the painted part or which frame outside of it.
Works on panel
My panels usually have 1/8 "thick and can be mounted or not on sub-frames.
When a subframe in pine is in place, this one is painted also and then adds a thickness to the work which can thus be hung as is on the wall. However, a framing is suggested to further enhance the work.
If the work is not mounted on a subframe, a framer can easily add one on the back of the panel to offer you a floating type frame.