For a window opening of width "W" and height "H“, you will need the following components:

1) Front panel 

  • Width = W + 2 cm, height = H + 2 cm 
  • Material = Polar fleece or another thick and flexible fabric that can fit snugly against the sides of the window opening and prevent the passage of air.  
  • If the Kume curtain is used as a primary curtain, the front panel can be made with a fabric that best suits the decor of the room (a cotton print for example).
  • You should ideally wash the fabric before making the panels and, as with all drapery, you should consider using flame-retardant fabrics. 

2) Moisture barrier 

  • Width = W - 2 cm, height = H 
  • Material = Transparent polyethylene with a thickness of approximately 0,1 mm.

3) Upper batten 

  • Section = Approximately 1 x 3 cm 
  • Length = W - 2 cm 
  • Material = Pine can be used for battens that are up to 3 m long. Battens for wider curtains should be made of sturdier hardwood.

4) Lower battens 

  • Section = Approximately 1 x 2 cm 
  • Length = W - 2 cm 
  • Material = Pine or hardwood. 
  • Number = The spacing between the battens should not exceed 50 cm, therefore the number of lower battens needed depends on the height of the curtain.

5) Back panel 

  • Width = W + 2 cm, height = H + 2 cm 
  • Material = Ideally polar fleece or another thick and flexible fabric. 

A) The front and back panels are a bit bigger than the window opening. This is because these pannels need to completely plug the window opening when the curtain is closed.
B) The choice of materials was mainly guided by our desire to make these curtains very affordable and, therefore, accessible to as many people as possible. This is why we chose polar fleece (which is inexpensive, insulating and widely available) for the curtain panes, and polyethylene film for the vapor barrier. However, many other types of materials can be used to assemble a Kume curtain. 
If you would like to use other types of materials, or even a different structure for the curtain (for example, using a quilted or interlining fabric to fill the gap between the front and back panels), please keep in mind the following points:

  • The fabric chosen for the front and back panels should ideally be thick, tightly woven to restrict the passage of air, and flexible so that it can accommodate itself tightly against the sides and bottom of the window opening. 
  • The curtain should have a moisture barrier placed behind the front panel. Without a vapor barrier you will get a lot of condensation against the cold glass, with a good vapor barrier you will get none.
  • The moisture barrier should be made of a thin, flexible and non-breathable material or fabric. 
  • The curtain should fit in the window opening and seal the full perimeter of this opening to prevent the cold air that forms against the glass from seeping into the room.