I've been thinking alot about edges recently. I had three requests to stain the edges of canvases I sold during my Open Studio event - which I was happy to do.
Normally, with a preliminary study, I leave the edges quite rough but fully appreciate some people want it to look a bit neater.
I've also been staining the edges of the nine small canvases which make up my painting 'Memento Mori.' I envisage them displayed in a box- like frame rather like a cabinet of curiosities so the edges need to be the same dark colour as the background, so they can dissolve into it.