9 x 12" First Class Flat Tyvek Envelopes. Tyvek envelopes provide superior puncture, tear and moisture protection. Constructed from 14 lb. olefin. Ten times stronger than paper envelopes. Feature self-seal closure. Available in plain, First Class...
9 x 12" First Class Flat Tyvek Envelopes. Tyvek envelopes provide superior puncture, tear and moisture protection. Constructed from 14 lb. olefin. Ten times stronger than paper envelopes. Feature self-seal closure. Available in plain, First Class...