Office Depot Lift & Press #10 White Premium Security Envelope Pack Of 500, lift & press closure provides a permanent seal immediately upon contact just lift the lower flap, then press down the top flap for an immediate seal. Tamper evident seal provides added protection of confidential materials. Security tinted inside for privacy and confidentiality. Made of crisp 24 lb white wove for a substantial feel. Forest Stewardship Council (FSC) for wood paper products from forests certified to the 'gold' standard of responsible forestry. Forest Stewardship Council US-0081. FSC Certification ensures responsible use of forest resources and provides assurance that the fiber in this paper comes from forests that are well managed to protect biodiversity and the livelihoods of the people that depend on those forests. Greener choice contains 100% total recycled content.