Trimantium

"The main superstructure has been reinforced, and trimantium plating lines the hull to provide the ship with unsually high tensile strength."

- C-D20 describes the HT-2200 medium freighter.

Trimantium was a metal which could be used to make armor plating for starships. The HT-2200 medium freighter model of ship made by the starship manufacturer Corellian Engineering Corporation had trimantium plating lining the hull which gave the ship unusually high tensile strength. The protocol droid C-D20 mentioned this feature when describing the model to to a Rebel looking for a freighter to use for his next mission.

Behind the scenes
Trimantium was first mentioned in 1995 in the article "A Buyer's Guide to Alternative Starships" which was published in the fifth issue of the Star Wars Adventure Journal series of supplement books for West End Games, Star Wars: The Roleplaying Game. The article was written by Stephen Luminati.