Smoothness and fluency to print. Long term stability and keep in normal condition. 1)Available size;37mmx50mm, 37mmx70mm, 44mmx50mm, 44x70mm, 44x76mm,57mmx50mm, 57mmx57mm,76mmx70mm, 76mmx76mm, 80mmx70mm, 80mmx80mm,etc. 2)Any other specifications could been requested by clients.3)Core pipe: cardboard core or plastic core. 3 1/8'' Red color thermal paper roll