The Costume Designers Guild has spoken their mind in 7 categories. Let's look at their nominees shall we?
Excellence in Period Film
The Dressmaker – Marion Boyce, Margot Wilson
Florence Foster Jenkins – Consolata Boyle
Hail, Caesar! – Mary Zophres
Hidden Figures – Renee Ehrlich Kalfus
Jackie – Madeline Fontaine
You might think "oh, that's the Oscar list!" but clutch your pearls or other design accessories. There are so many more options for the Academy in period that missed here (Silence anyone?) and in the other categories with Contemporary (which might have a contender this year with La La Land) and Fantasy nominations... which Oscar takes almost as seriously as Period Pieces in this category...