13.56mhz RFID chip is effected greatly by metal or water that is why we have to put ferrite or on metal layer into RFID sticker . It will use ferrite material can stop metal to interfere electromagnetic field application and make high frequency rfid label can work well whatever it stick on metal or without metal environment .This ferrite material softer and easy to make sticker on flat or curved item . Widely using in metal shelf management ,gas tan , cans tracking ,etc.