Which material is most commonly used for constructing a darkroom door?

The most commonly used material for constructing a darkroom door is lead. This is because lead is highly effective at blocking light, which is crucial for a darkroom setting where film and photographic materials are highly sensitive to light exposure. Ensuring that no light leaks in is essential for maintaining the integrity of the developing process.

Lead doors often have a significant thickness, which helps to absorb any stray light, thus providing an environment that is completely dark for photographers working with light-sensitive materials. Additionally, lead's durability and resistance to various environmental factors make it a practical choice for the demanding conditions of a darkroom.

Some alternative materials, such as wood, aluminum, and glass, could be used for darkroom doors in specific contexts, but they do not provide the same level of light blocking as lead. Wooden and aluminum doors might require additional seals or curtains to prevent light leakage, while glass would not be suitable due to its transparency. Consequently, lead stands out as the most effective material for this application.