I removed the old, original brake hoses from my bike to replace with new, stainless Galfer lines. A couple things surprised me...the first was the manufacture date stamped on the hoses, 5/83. 40 years ago? Wow.
The other was the makeup of the hose. I assumed they were all rubber but they are multi layered. A rubber outer cover, woven fabric inner layers and a reinforced rubber inner core. The internal diameter is smaller than what I would have thought, too.
Interesting to see them cut and opened up.