Another variable to consider is glare visible on the drawings. This is usually only localized where pencil is used on the drawings. Removing this factor would be preferable as it can be a distraction and even a hindrance to the viewer.
In the experiment done the other day, when the drawings were placed higher up the wall some of this shining disappeared. I figured to remove it more completely the drawings would have to be slightly tilted. The bottom of the drawings would come out of the wall a bit more. This will have to be Incorporated into the baton hanging on the back.
