All of RFID and NFC products are made of NFC wafer, NFC antennas and substrates. Substrates can be PET, paper stickers, PCB, FPC，ABS , silicone, fabric, coils and the others. By the way, all of RFID NFC substrates can’t be any metal materials. If it must be applied on metal, tags need to be anti-metal materials or enlarging its thickness or increasing antennas. Because all of RFID NFC antennas mostly are made by coppers, silver or aluminum. To a certain extent, metal materials would elevate original standard frequency, as frequency going high, read distance would be off optimal point, so if using NFC tags on metal, read distance would be around 1/2 or 1/3 to original normal NFC tags in standard condition. If no needing to use on metal, it is recommended to use normal NFC tags, whose read distance would be better and also save costs.  About NFC wafers manufacturer, for now, there are 12 companies, there would hundreds of wafer types can be offered. Below is the NFC wafer provider name as below, if it is no ideas to choose suitable NFC wafers, please  contact us.