Mazzucchelli 1849 Acetate Production 

Some random data: The typical Brown and yellow pattern on Eyeglasses named havana or tortoise its an imitation of the shell of some species of tortoises that were hunted from centuries for making eyeglasses, combs etc. the substitute in acetate was cheaper because the tortoises populations were largely reduced and the original tortoise shell cost was prohibitive. Real tortoise shell was used into beginings of 1900s when it fall out of use.

Excellent video - very relevant to stuff I'm doing, gave me some good ideas. Thanks for posting, Johann.

very nice job

Super nice video, i love it, and it's just nice to see how the plates are made

Yo le sang

Este proceso evita matanza de tortugas

trabajo para la óptica mas visión y estoy aquí porque me dió curiosidad que es el acetato de los armazones que vendo