New Guardian manilla envelopes are made from strong environmentally friendly two-tone premium paper, perfect for protecting your mailings. These Envelopes give you excellent value for money. The heavyweight nature of these envelopes are the ideal choice for mailing heavier or bulky items. They feature a handy peel and seal closure so there is no need for tape or licking. They are pocket opening; meaning that they open along their shorter side, which gives your mail a professional look. Accredited with Paper by Nature confirms their commitment to the environment.