How Do I Make It
1. Lay insulation out flat on a clean surface. Lay the 0.66oz membrane 10 taffeta nylon on top and the hyperD nylon on top of that.
2. Measure, pin, and cut the fabric out as per the dimension drawing. Adjust the dimensions if you need to. Add at least another inch on the top of the inside fabric for the draw cord. I rotated this extra fabric to be folded in between it and the outside fabric (when you sew and flip it inside out the draw cord will be showing). You can add the cord and tightener here, just make sure to sew over the edges. Rotary cutters are a lot easier to cut the fabric/insulation compared to scissors.
3. Sew the fabrics together along the top and down the sides at least 40 inches. This leaves out the future footbox and the sides that'll be sewn together. Be careful with the draw cord area.
4. Turn the fabrics inside out so the insulation is on the inside.
5. Sew the lower tube of the quilt together omitting the inner fabric. This should be the outside fabric and insulation together in tubular form, for the last 28 inches on the sides.
6. Sew the circular footbox section of the outside fabric and insulation to the bottom of this tube (ommitting the inside fabric). Add an elastic loop to this if you'd like it to be hangable.
7. Sew the inside fabric together along the sides in tubular form. Sew the circular fabric piece to the bottom of this.
8. In the footbox, sew a few points on the inside fabric to the rest of the bag. This will keep the inside fabric from coming out.
9. Add buttons along the sides as desired. You can make separate pieces of elastic with buttons on them to make it more open in the back.