Blood And Black Lace (1964)

Starring Cameron Mitchell, Eva Bartok, Thomas Reiner, Ariana Gorini, Dante DiPaolo
Directed by Mario Bava
(actor & director credits courtesy IMDB.com)

The beautiful models of a fashion salon become the targets of a vicious murderer, who assaults and tortures them for the secrets hidden within a scandalous diary.

An extremely stylish Italian thriller from director Mario Bava, it's also a very entertaining one with the killer's identity kept a mystery until late in the film, although Bava gives us some visual hints.  The cinematography by Ubaldo Terzano (and per IMDB, an uncredited Bava) is superb, with a grand and beautiful color scheme, and effective use of a roving camera.  Composer Carlo Rustichelli contributes some haunting themes, and the performances are excellent.  I was entranced from the dynamic opening credits sequence, which has the cast pose like the models of the film, and although I was disturbed by the violence committed against the film's victims, which made me very uncomfortable, I understand how this approach heightened the suspense and made the killer's assaults more terrifying to the audience.  Bava here has crafted a film that not only looks spectacular, but is intelligent and gripping on the same level.