Google is not all bad. They sent me this page showing a bias cut dress from the thirties/forties.

https://g.co/arts/8rrUK26tnXRAhJhX9

#FashionHistory #HistoryOfDress #BiasCut #IndianapolisMuseumOfArtAtNewfields

evening dress - Google Arts & Culture

A bias cut gown of black crepe backed satin with sheer leaf and rose patterned lace cap sleeves and back neck flounce. Front of gown: V-neck; multiple rows...

Google Arts & Culture