Perhaps a large hole for inlet to booth. You can use those cheap 1" furnace filters. You don't want it to be too restrictive. Large hole so you don't get a noticeable breeze. I can adjust the opening of the fan, will play with that after I get the frame wrapped up. Best to have garage door closed to control the temp. Yep...also helps with the lighting, believe it or not What temp will you be spray at? I found 70F ideal. Make sure compressor is drawing in air from a clean source and around 70F. If everything goes well, hope to shoot this weekend. Forecast is 78/68 Sat - 71/61 Sun after front. I don't know what your temps are there but don't let the booth get cold before or after as you might get condensation on the ceiling. A good stable clean air environment will ensure the paint flashes over properly with no sags etc. I'm a self taught painter, learned the hard way! Painting your own car is VERY gratifying work Thanx for the advice, your right, this whole project has been verrry satisfying...at least up to this point ;-)