Antique nainsook apron with lace trim. Source: Etsy.
AKA Nainsouk.
Part of the ‘Antique Fabrics‘ series, this fabric isn’t necessarily extinct, but it was more popular in the past than the present.
A thin, delicate plain-weave cotton. Very soft. Popular for lingerie and infants’ clothing. Originally imported from India, the name derives from the Hindu word nainsukh (“eyes’ delight”).
Today, it’s still made from cotton, usually long-staple fibers which result in a finer, stronger fabric.
For a good-enough substitute consider cambric, percale, or batiste, although the latter might be too sheer for your project.
Fabric For Cosplayers