Purple Plastic Wristband: Comfortable, stretch resistant, and using a one time locking snap, purple plastic wristbands are ideal for multi-day use. These wristbands are waterproof, lightweight, strong, ultra stretch-resistant and much more durable than Tyvek wristbands. The draw back with purple plastic wristbands is they are two to three times more expensive than Tyvek.
Compare for yourself: Plastic & Tyvek Wristband Pricing
Also note that custom printed plastic wristbands have a 7 day turn-around time compared with 2-3 days for Tyvek. Comparatively speaking, plastic wristbands do have a higher quality appearance as the material is thicker, and glossy compared to the flat thin soft feel of Tyvek. If image is important to your event and you have the proper lead time, purple plastic wristbands may be the best option for you.