10 x 13" 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...
10 x 13" 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...