3-ply mask typically refers to a type of face mask constructed with three layers of material:

1. Outer Layer: Usually made of non-woven hydrophobic material, this layer repels fluids and moisture, acting as a barrier against splashes and droplets.

2. Middle Layer: This layer is often a melt-blown fabric designed to filter out particles and provide filtration efficiency. It serves as a barrier against smaller particles and airborne contaminants.

3. Inner Layer: Made of soft, non-woven material for comfort against the skin, this layer absorbs moisture from the breath, making it more comfortable to wear for extended periods.

These masks are commonly used in healthcare settings and for general protection against respiratory droplets and particulate matter in the air. They offer a balance of protection and comfort due to their layered construction.