Please note: most square envelopes require additional postage. 9 x 9 Square - 30lb. Translucent - Natural Translucent (vellum) paper, made from 100% pure cellulose fiber without the use of resins or other transparentizing agents. Has outstanding formation and translucency, and are recyclable, acid free, and elemental chlorine free. Great for use in direct mail, announcements, special events, invitations, or general use. Buy more to save more.