These Quality Park catalog mailing envelopes feature a quick-and-easy Redi-Seal closure ideal for bulk mail Redi-Seal envelopes have pressure-activated latex adhesive on two surfaces Just press together for a strong durable seal No paper strips No moisture required Redi-Seal envelopes are the perfect mailroom update for concerns about surface germs in the workplace Skip the yuck save time and cut waste with every mailing These self seal envelopes are inkjet printer compatible though not recommended for the laser printer Made of 28 lb stock that can withstand extensive handling through the mail Center seams give added strength for heavy contents Seam Type- Center Flap Type- Cheese Blade Trade Size- 13 1/2 Security Tinted- No