Store important documents in these acid free envelopes. Colorful, durable poly material is tear & water resistant & easy to clean, making these envelopes great for keeping everyday papers organized too. Tough & acid free, these clear envelopes are ideal for the home or office. Expands 1.25". String-tie closure to secure contents. Closed on three sides for security & portability. Open-SideHorizontal orientation. Seam Type: Weld; Flap Type: Cheese Blade; Security Tinted: No; Opening: Open Side.