3/4" Tyvek Wristbands have never let me down!
I have been buying these for years to use as entry wristbands for the concerts we have here in our senior community. I buy the white ones and then use my laser printer to print the seat number on each one for the 500 or so attendees.
They always arrive quickly and the quality is great.
Note: The laser printer ink will run if they get wet.