In order to display books, artwork, or china its best to have either a groove or a small lip to help keep things upright.
We can cut a 1/2″ wide by 1/4″ deep V-groove for $25 per shelf. 
To add a ¼” X ¼” lip we can do for $40 per shelf. The lip has to be at least 1/4″set back from the front edge.
In either case we will need a simple dimensioned sketch showing the location so we can get it right.