How do I know if I'm feeling some kind of lining in a suit jacket or if its actually canvas? 'Lining' is the smooth silky stuff (usually made of rayon/bemberg/etc) which is visible covering parts of the inside of a coat, used to add warmth and to make it slide on easier. Lining is attached with pleats and ease to give it a certain amount of looseness. 'Canvas' is rougher fabric which is used to add body to the fabric, attached without ease to the rear side of the main fabric, usually (but not always, if there's minimal or no lining) enclosed and not visible from the inside. Any non-fusible used to add body in this way is referred to as 'canvas', even though many of the fabrics used may not technically be canvasses. If you're asking how to tell the difference between a fused and a canvassed coat front, then this has been discussed countless times, but the most common method is the 'pinch test' (do a search).