The black box exposure is used primarily to recreate the exposure conditions of the horizontal surfaces of an automobile. The "box" creates an enclosed air space beneath the panels which form the top surface of the box. The modified environment is similar to that of a parked automobile.

The black box can be used at a number of exposure angles. However, for automotive testing, the black box is usually placed at 5 degrees.

The box is made of aluminum, painted black, with the test panels forming the top surface. The black box also serves to lower the panel temperature overnight below that of the surrounding air, creating a longer condensation period.