What an Awesome Find! The 3/8” Felling Foot
I make doll tights and for the 1/4” elastic casing for the waist, it’s very difficult to get the seam exactly straight and look good all around, on both inside and out. When I first started making these tights, I tried to get it exactly how the original doll tights were from the manufacturer, which was overcasting the edge and sewing the elastic directly to the fabric rather than using a casing. So I ended up with something like this: