In my shop I sell what I call wall art boards. It's one of my prints mounted to a painted piece of wood with a sawtooth hanger on the back. I paint and seal the sides and the back. I was shopping at a craft show in NYC yesterday and noticed that other vendors who were selling their prints mounted to wood didn't paint the back. (One didn't even paint the sides.) These pieces were a similar size and pricepoint to mine.
It obviously adds extra time to my production process to paint and seal the back. (I usually do two coats of each.) Put yourself in the shoes of the buyer. Does the painted backside add value? If not, should I skip it and save myself the time?
Here is a listing for one of the pieces so you can get a better sense of what I'm talking about. The second image is a photo of the back. Thanks for your help!
http://www.etsy.com/listing/85836305/plum-wall-art-cabinet-of-curiousities