To calculate the amount of lining required to make an interlined blind again we need to establish the Cut Width and Cut Drop of the lining which are slightly different to the fabric:
LINING CUT WIDTH
The lining is narrower than the fabric and the Cut Width is equal to the Finished Width of the blind.
- Cut Width (lining) = Finished Width of blind
LINING CUT DROP
The lining is longer than the fabric though due to the rod pockets. To calculate the cut drop of the lining add a 5cm heading allowance, a 2cm hem allowance and an allowance* for each rod pocket to the finished blind length.
(*The rod pocket allowance is the circumference of the rod plus 1cm, our fibre glass rods require a 2.5cm allowance.)
- Lining Cut Drop = Finished Blind Length + 5cm heading allwnce + 2cm hem allwnce + (2.5cm*) per rod pocket
LINING QUANTITY REQUIRED
The calculation for the amount of lining required to make an interlined blind is
- Multiply the "Number of fabric widths" by Cut Drop (for lining).
INTERLINING QUANTITY REQUIRED
The amount of interlining required is the same as the calculation for plain fabric.