What is the best method of hanging canvas on a wall to work on? I've seen several videos and images of artists having their canvas stuck on the walls - paintings that they are currently working on.

I was wondering how they stick/place it on there?

These canvases are still unstretched and aren't framed, like those in the background of this picture:



I've tried using sticky putty but it isn't so effective when stuck on canvas.  Also duck tape isn't so effective.

Would appreciate any help, thanks!
Staple gun or hammering finishing nails to the wall. How will it be presented after completion?