my attempt at a spray booth (knockdown type)

Nice! Any issues with the lights and fumes?

there shouldn't be . I'm going to cover them with the M-D building product's (hillbilly weatherproofing ) clear plastic that you cover the insides of your windows/door walls using double tack tape. stick it on and heat shrink it to stretch it tight then trim it. I'll then do the rest of the areas with 6mill poly sheet and man's best friend duck tape!