Mounting Paper for Pastel painting

Sanded paper can warp slightly when wet. I prefer to use rubbing alcohol when working an under painting because it dries quickly. However, a generous spray of alcohol can still warp the paper slightly.
​Taping my paper down before painting not only keeps the paper flat as it dries, but it creates a nice edge for the finished piece.  

In the photos above, my recent painting is taped to the corrugated plastic used as a backing.
Sometimes I will lay down two strips of tape, one over the other, to prevent the tape from peeling (the alcohol can dry the tape causing it to lift). 

When the tape is pulled away a clean, straight edge is left.
​If pastel dust finds its way onto the paper, a kneaded eraser will easily pick it up. 
Because I don't paint all of the layers to the very edge of the tape, the paper colour and the process including the under painting is left visible to the viewer. 

Rarely do I paint a picture to fit in a frame. I purchase frames to fit the size of the finished painting.
Sometimes, despite careful planning, I'm not happy with the final layout and will crop the image even further. 
In that case, the clean edge is no longer visible.
For the well planned and nicely executed paintings, a clean edge offers a little glimpse into the layering process from start to finish. 
Do you have any taping or paper-mounting tips to share? I'd love to hear from you! Leave a comment below.