Mounting brackets for Kallax shelf

I have a four by four Ikea Kallax shelf next to my desk which serves as a room divider. The side which faces to my desk is not the side where I handle its content and the view on it isn't very nice. First I thought about a hardboard as rear wall but I don't expected that this will look nicer than the current view. So I designed and printed little brackets for each corner that I can mount dividing walls in each square with a suitable design I want.