How to Add a Slit (without seam) Spaghetti Straps Satin Black Prom Dress Evening Gown With Slit PSK553 Custom Size Black Sweetheart Mermaid Prom Dress w Corset Bodice & Slit How to add a slit where you dont have a seam. I had made a dress but wanted to add a slit to it once it was done, so didnt have a seam where I could add one easily, so this is the method I used!, Draped White Chiffon Cut out Slit Unique Prom Gown