Interfacing is generally used to give fabric a bit mure structure e.g. collars, bonnets etc. It is easily applied by placing the shiney side onto the fabric and ironing on. 
Width - 36"
Priced per metre. Other lengths available. 
This product is suitalbe for crisp cotton and coton blends only. 
Washable
Medium heat when applying. 
Priced based on bulk order p/m