Step 1. Measure the windows to be treated with thermal curtains. Be careful on how you convert your measurements into the fabric yard.
Step 2. Obtain the batting material and decorative fabric material. It is best if you can use recycled or sustainable material. Keep in mind that you want sturdy material that is not going to stretch or rip easily. Twill works best, while jersey is impractical.
Step 3. Wash the decorative fabric material before you fabricate your thermal curtains.
Step 4. Cut the batting material and the fabric out according to the measurements of the window, giving an allowance of 2 inches around the perimeter of the decorative fabric material. Remember, it is better to be a little over than too short.
Step 5. Pin the fabric on to the batting material so that it makes sewing easier. With the Warm Windows batting material, the fabric-side of the batting material must face the decorative-side of the fabric material.
Step 6. Use a sewing machine to sew the fabric to the batting material.
Step 7. Make holes in the material along the top for the grommets to be put into.
Step 8. Sew Velcro onto the sides of the curtain panels that need to be sealed onto the wall. Position and set Velcro on the walls relative to the position of the Velcro on the curtains. This allows for better insulation.
Step 9. Install the curtain rod and hang up the curtains.
Step 10. Make curtain ties out of the extra material, if any, if you want to be able to tie the curtains back.