Lifestyle Style Kourtney Kardashian's First Clothing Collection for PrettyLittleThing Got Kim and Khloé's 'Stamp of Approval' Kourtney exclusively spilled all the details about her first solo fashion collection with PrettyLittleThing By Kaitlyn Frey Kaitlyn Frey Instagram Twitter Assistant Style & Beauty Editor, PEOPLE People Editorial Guidelines Published on October 25, 2017 01:00 PM Share Tweet Pin Email In the 10 years that Keeping Up with the Kardashians has been on the airwaves, each of the sisters has become a fashion and beauty mogul in her own right. Kim has KKW Beauty, Khloé has Good American, Kylie has Kylie Cosmetics and Kendall has become a bonafide supermodel. Now Kourtney‘s cementing her footprint in the fashion world, too. The eldest Kardashian sister and mom to Mason, 7, Penelope, 5, and Reign, 2, is launching her first solo fashion collaboration with PrettyLittleThing, available starting tomorrow at 12am PST. The 32-piece “Studio 54, old Hollywood and ’70s-inspired” collection of sexy sequin mini dresses, faux fur jackets and sparkly biker shorts has Kourtney written all over it — but she didn’t go through the whole design process without a few opinions from her sisters (she is a Kardashian, after all). Pretty Little Thing “I see my sisters almost every single day, so while I was designing the collection, if I was going over fabric swatches and they were sitting next to me, I would ask their opinion, like confirming, ‘This is really a good dress, right?’ to just kind of get their stamp of approval,” Kardashian told PeopleStyle. Looking for more style content? Click here to subscribe to the PeopleStyle Newsletter for amazing shopping discounts, can’t-live-without beauty products and more. Pretty Little Thing Of course, Kourtney is no stranger to putting her mark on the fashion world. The KUWTK star teamed up with her sisters in 2011 to launch their first clothing brand, Kardashian Kollection, sold at Sears, but this time she was ready to be the woman in charge. “With my sisters, we would always have to incorporate each other’s style into the collection. A lot of times Kim and Khloé would agree and maybe I wouldn’t agree, so we’d have to have a two-against-one rule,” Kardashian told us. And her love for clothing design extends well beyond her time in the spotlight. The 38-year-old studied fashion design in high school and costume design in college, and still owns the same sewing machine she started using as a teenager. PrettyLittleThing “I used to sew my friends’ clothes on the weekend if we were going out and they wanted something, just for fun,” she told us. “My love of clothes since I was so young – playing in my mom’s closet and even my passion for interior design – has helped with this.” In the end, once Kim and Khloé saw their sister’s final pieces, they totally approved of Kourtney’s work. “Khloé wrote me because she was out of town a lot when I was doing it, so I mostly showed it to Kim, but she was like, ‘Oh my god, congratulations. The collection looks amazing. I am so proud of you,'” she said. PrettyLittleThing Although at times on their hit E! reality show, fans see the sisters bicker and fight (can we all take a moment to remember Kourt and Khloé ruining Kim’s Bentley moment?) when it comes to their separate businesses, they’re each other’s biggest cheerleaders. “We’re 1000 percent supportive and there’s no competition at all,” Kourtney said. “I send inspiration to them all day. Like, if I am looking online and I see a cool ’90s makeup vibe, I’ll send that to Kylie.” PrettyLittleThing When designing her party-appropriate pieces, Kourtney always had one request: “I would always say, ‘This needs to be shorter, shorter, shorter!'” the petite 5-ft.-o-in. star said. “When I buy something I usually have to tailor it and shorten everything like four inches, but these dresses I didn’t have to do much at all.” RELATED PHOTOS: 14 Unforgettable Style And Beauty Moments From the Past 10 Years of Keeping Up with the Kardashians The pieces in Kourtney’s collection are affordably priced ranging from $12 to $115, which was a conscious effort she made to reflect her interest in mixing high fashion and lower-priced pieces. “I love an expensive shoe, so I like mixing an expensive shoe with a more affordable dress,” she said. “I think it’s all about wearing what you love and what makes you feel sexy. PrettyLittleThing Even though Kourtney’s PrettyLittleThing collection is totally inspired by her own style, we still had to ask her which pieces she would dress all of her family members in. Pretty Little Thing Buy It! PrettyLittleThing by Kourtney Black Embellished Oversized Blazer, $90, Bronze Metallic Cycling Shorts, $24 and Burgundy Faux Fur Coat, $115; available October 26th at prettylittlething.com “I would say the bike shorts are so Kim. One of the colorful furs is definitely Khloé. Kendall, maybe the oversized blazer that you could wear over the bike shorts or as a dress with belt. I would love to see how Kendall would wear that,” she told us. “Kylie is definitely a dress girl — she’d be in one of the sequin dresses. For my mom, there’s a really cool high-neck black long sleeved dress with openings on the side. I could see Mamacita in that.” Pretty Little Thing Buy It! PrettyLittleThing by Kourtney Black Bandage Lace Up Bodycon Dress, $90 and Silver Sequin Bodycon Dress, $70; available October 26th at prettylittlething.com And as for herself? “My favorite piece is the black satin jumpsuit. I love that you can wear it from day-to-night, with sneakers, with boots, with heels or a belt,” Kourtney said. “There are a lot of different ways you can wear it.” Buy It! PrettyLittleThing by Kourtney Black Extreme Oversized Jumpsuit, $70; available October 26th at prettylittlething.com What’s your favorite piece from Kourtney’s PrettyLittleThing collection? Tell us in the comments below.