Ok so you probably know that Clueless (1995) is an adaptation of Emma (1815), and the costume design references the Regency period occasionally, like in this green empire waist* dress:
Here's a Regency day dress if you're not familiar with the era:
My favorite Regency reference, however, is Cher's Calvin Klein shift dress, which her father says "looks like underwear."
Here's some 1980s slips (which were, in fact, underwear) for reference:
And in fact in the Regency period, plain white dresses that "looked like underwear" were the biggest fashion trend of the day. Way back in 1783 Marie Antoinette was painted in this dress, causing a huge scandal:
At the time, women's base layer of underwear was a white dress called a chemise that their stays et al went over, and this style of dress resembled it too closely to not be daring, racy, and insolently casual. Here's a chemise:
(There's also a bunch of stuff about class tied to this style of dress but that's not important right now.)
By the 1810s, simple white dresses had stopped being shocking and were all the rage, and they are EVERYWHERE in Regency fashion:
Which is echoed in Cher's 1990s equivalent. Love how the costume designer** manages to call back to Emma without using the Regency silhouette.
*the phrase "empire waist" in fact refers to this time period and the First French Empire (that's Napoleon)
tangentwithtanner
stormborns
annaxmalina
discoholicmusic
blakekathryn
