A hybrid type of door is available consisting of a strip curtain that rolls up on roller, which is usually motorized. This type avoids the annoyance of having to push through the strips. To keep the strips from jamming along the side of the door when the curtain rolls up, the strips are cut in a tapered shape. This type of door is not as effective as the tightly sealing roll-up doors recommended by Measure 6.2.5.4, but it is less expensive. The tapered shape of the strips sacrifices sealing at the sides of the door, and the door may not be well sealed at the top.