Talk:Carbon Fiber/@comment-39616607-20200225053442

I get carbon fiber by commissioning the Civil Corps. This allowed me to get hundreds of them back when I was still in mid-game, long before Deepest Ruin unlocks. The Civil Corps can bring you 45 every 1-3 days. Even more if you marry Arlo or Sam.

For me, on PC, Carbon Fiber showed up in the list for Ingall's Mine Middle and Lower Level before getting the mission to build The Dragonfly. After I got that mission, Carbon Fiber disappeared from the list but is still rewarded.