Thermal Transfer BOPP - This is a synthetic material which can be printed on using a thermal transfer label printer. BOPP stands for Bi-axial Orientated Polypropylene.
This means it cannot be torn easily at all in both directions and will only stretch a small amount if stretched.
This is commonly used where labels have to go outside and be exposed to water. Common uses are plant nurseries, hardware stores, asset labels, jewellers etc.