Vanity Fair Tricot Double Slit 18 Inch Slip (1171718). The Vanity Fair Tricot Double Slit 18 Inch Slip 1171718 features a sewn-on inner elastic waist and deep, curved double side slits. Vanity Fair's Tricot Double Slit 18 Inch Slip is made of silky 100% nylon tricot knit.