While plus size 70s reproduction clothing is not as easy to find as that from other eras - such as the 1950s, especially rockabilly dresses - it is out there. However, depending upon what you want, you may need to be prepared to either do some sewing or have it done for you.
Plus Size 70s Reproduction Clothing Options
Despite the popularity of a few select items, such as halter jumpsuits and platform heels, modern reproductions of 1970s day and evening wear are not a major industry. Women who want vintage and retro styles are still gravitating mostly towards the styles of the 1940s and 1950s. There is a taste for some aspects of 1930s clothing, especially in evening wear, and the popularity of the TV show Mad Men has spawned a resurgence of interest in 1960s clothing. But actual, wearable 1970s fashions are not really being made - when you see someone wearing 1970s clothes, they most likely either found them in a vintage shop or sewed them from a vintage or reproduction pattern.
What you can find are costumes, and many of these can be of good quality - although they are likely best used for club wear.
Additionally, there are plenty of patterns available. Having something made is often the best way of assuring you have something that works on your body and is exactly what you want.
Even when searching for costumes, plus size 70s reproduction clothing is limited. You can find a few cute things at Anytime Costumes. They have a black and gold disco dress in a swing style with a black sash that fits up to a size 22. It falls to just above the knee, has a flattering draped bust in a sweetheart neckline and open cap sleeves.
You can also get a "disco diva" dress that allows you to seriously get your psychedelic on. This is a very cute and sexy black and silver mini dress in a swirly pattern. It's made of polyester and trimmed with sequins. It's got long sleeves that flare from the elbows, a scoop neck and a groovy matching head scarf. It fits up to a size 22. You really want to get some classic go-go boots to match.
Although it's a bit terrifying, the "plus disco licious" two-piece suit is the 1970s club scene at its best. It's a peach paisley psychedelic outfit with a bell-sleeved top and bell-bottom pants that are split to the knee. It comes with a matching neck scarf and fits up to a size 22.
If you're not looking for plus size 70s reproduction clothing that is absolutely exact to the period, you can find certain things easily, such as very flattering halter top dresses and jumpsuits. What you want to be careful of is an outfit that cuts you in the middle. Bell-bottoms can be very flattering when worn with platform shoes as they lengthen your silhouette, but you want to pair them with a top of the same color if possible.
The one way to get a great disco outfit that you know works for you is to make or have it made. Unlike sewing patterns from the 1940s, those from the 1970s used sturdier paper, clearer marks for cutting and darts and were overall easier to follow. Additionally, many more of them are available. Until recently, they were considered fairly undesirable, so the prices have traditionally been quite low. Most web sites selling patterns will have a good selection of 1970s items. The challenge is finding one that is already plus size. However, if you find something you love, an experienced sewer will be able to size it for you so that you can at last have the 1970s outfit of your dreams.