Not neccessarily. If the portion above the railing and ceiling are painted the same light shade, it will give the appearance of more space in the room, effectively enlarging the ceiling.

Yes but I'm not painting. I'm
Upholstering so it will be puffy. The ledge stoking out could potentially be odd looking.

It's seems as though there out to be a way to trim the padding that goes over the walls to accommodate the ledge then just cover the walls flat.

There is, but it seems an odd look? Would you consider removing the ledge and upholstering to the ceiling? Otherwise, if the padding isn't too thick and is stopped before -rather than at - the ledge, the effect will taper up to a flat surface. The ledge should be removed to allow the fabric to continue up the wall, and remitred to fit over again.

This is a rental. If its not too hard to remove gone ledge and replace it when iMovie, perhaps I'll just do that!

HI -- I don't understand why you are going to this expense and bother for a rental space . If I was your landlord I would not want you to be stapling fabric to the walls or removing picture rail trim . If the walls are an applied plaster finish you could be causing a lot of damage . You could just wallpaper or better yet you could just sort of glue the fabric to the walls using liquid starch and the fabric can then be removed when you leave . Just paint some starch on the wall and apply fabric then paint more starch over the fabric and let dry . There no damage ! Leave the picture rail alone , too risky to mess with.

I've been sparing expense and not living that bedroom for ten years now. I'll be another five years and its worth it. If the ledge is the sort easily replaced ill do that.

Rather an important detail to leave for last, mjtisor! Try not to get yourself sued for the sake of batting, and good luck in your new space.

Oh nono. If anything, the upholstery can be removed. It's a good option for a rental.

I'll post pics when it's done. Can't wait.