I cut a slot in the top of mine about two inches wide, and about 3/4 of the width of booth. I glued a strip of clear plastic inside to keep paint fog off light source, which is a fluorescent strip (cabinet) light.
To keep the paint fog from clouding that plastic strip, I make tear-offs, like racing drivers and motorcycle racers use over their visors.
I use that clear packaging tape. I lay down the first strip on a piece of glass. Then I put down several more layers on top of it, folding back the last half inch to create a tab to easily remove that layer when it gets tinted by paint fog. When I get several such strips down, I peel the whole thing up from the glass and stick it to bottom of the plastic window.