Companies with in-house photography teams need a fully light-tight dark room to develop film, process photos and calibrate professional screens, and this kind of space requires partitions that can completely block all external light and maintain a stable dust-free environment. EPS Cement Sandwich Panel is the ideal material to build this kind of specialized office space, as the seamless joint connection system between panels creates a completely continuous wall with no tiny gaps that external light can leak through. Unlike drywall partitions that almost always have small cracks at seams that let tiny amounts of light leak into the room, these panels can be sealed completely with specialized light-blocking sealant to create a 100 percent light-tight space. The moisture-resistant surface of the panels can also handle the high humidity levels that are common in film development dark rooms, without growing mold or warping. The excellent sound insulation performance also blocks external noise from entering the dark room, so the team can work in a completely quiet, distraction-free environment. Many in-house photography teams that built their dark room with these panels reported that they achieved perfect light-tight performance on the first test, with zero unwanted light leaks ruining their film development work.