Intertherm Medium Non-Woven Sarille 220gsm WhiteIntertherm Medium Non Woven Sarille 220gsm White. Create opulent window treatments with curtain interlinings, which are designed to improve the drape of the curtains and provide a luxurious appearance. Not only do they create designs with prominence thanks to the density of the interlining, they improve thermal and sound insulation levels too. A medium weight interlining, perfect for adding body for a fuller look. It is ideal for medium weight