The warp yarn is dyed with indigo, and by the 1920s, synthetic indigo was fast becoming popular. But synthetic indigo was produced by a German company, and US manufacturers weren't supposed to use it. In 1918, the type of indigo you used was a political decision.
We often get chaps wearing peculiar hats adorned in bright colours wandering in to the Centre and they all say the same thing – ‘you won’t guess what we are here for’. Yes we do. Fly fishing. When 80s Bulk, which looks matt on the bobbin, is wrapped very tightly then the brightness of the yarn appears. It is resilient, stretchy and takes dyes so well that the colours are magnificent. The fish rise!
By way of example, Weitz in the same article by Louie on why the modern menswear designer simply must work with new tech fabrics and synthetics: “I design in blends for two reasons. There are no more servants, and wives don't want to iron.”
The design problem Weitz seeks to solve is: how to keep a man looking like he still has servants or a wife who likes to iron, even if society has “degenerated” to the point that a man simply no longer has reasonable access to servants and a wife who likes to iron. Modernity, therefore, becomes the embrace of the technology that restores the norm, not the revolutionization of the meaning and look of the norm.