IRR
From Night Vision Wiki
Textiles used for modern infantry clothing or equipment are often IRR (Infrared Reflective) / NIR (Near Infrared Reflective) treated.
IRR treated materials effectively extend the materials shade or camouflage pattern into the near infrared spectrum.
It is a common misconception that IRR treated materials absorb most infrared light. Instead, the main goal is to provide effective camouflage that breaks the silhouette of the wearer when observed using night vision. The same principles of camouflage that apply in the visual spectrum also apply in the near-infrared spectrum:
- Darker is preferrabe to brighter shades.
- Breaking the silhouette using patterns and different shades is preferrable to a homogenous color palette.