Cortosis-weave armor was an armor which was resistant to lightsabers. It contained traces of cortosis, an ore prized for its ability to create an energy feedback loop which would temporarily shut down a lightsaber.
As cortosis weave contained only trace amounts of the ore woven into it, the armor lost the ability to short out an opponent's energy blade. Instead armor containing the cortosis weave would merely be resistant to lightsaber strikes.
Cortosis weave was in use as early as 4000 BBY as both an armor underlay and for the tempering of traditional melee weapons against lightsabers. At this time cortosis ore seemed to be much more common, later, however it would become a rarer, more valuable material that would give the user an unexpected edge against a force-sensitive opponent.
The armor was known to have been used by the Yinchorri in the 33 BBY Yinchorri Uprising. A variation was also used by the Jensaarai Corran Horn and Luke Skywalker fought in 11 ABY on the planet Susevfi. The Jensaarai customized their armor with cortosis weave patterns for decoration, although it retained the more pragmatic abilities of the armor. The cortosis used in their armor was smuggled from the gas planet Bespin. Shadowtrooper armor worn by the force sensitive troops of the Empire Reborn battled by Kyle Katarn and the members of the Yavin 4 Jedi academy in 13 ABY also contained cortosis weave.
- Star Wars: Knights of the Old Republic
- Star Wars: Knights of the Old Republic II: The Sith Lords
- Darth Plagueis
- The Cestus Deception
- I, Jedi (First appearance)
- Star Wars: Jedi Knight II: Jedi Outcast
- Vision of the Future (Mentioned only)