superduper Collars are made from three pieces of fabric, the top collar, the under collar and interlining that is sandwiched between. Interlining is basically another layer of fabric of comparable fiber composition. The interlining give the collar the stiffness and “body” that allow the collar to stand up with a rigid formal look. The stiffness and drape of a collar can be altered by changing the interlining. Also the interlining is cut on bias to give the collar a better “roll” at the top edge. World class shirts do not use press-on fusing, similar to fine bespoke suits do not use press-on fusing. The reason for this is longevity of the shirt. No matter how wonderful a shirt looks with crisp press on fusing, after enough washes the glue of the press on fusing will start to fail and you will see bubbling. This is especially noticeable at the collar roll/fold that gets the most wear and tear. A stiff interlining not fused into your collar will give you the same look, it is simply much m