These Quality Park catalog envelopes feature a quick-and-easy Redi-Seal closure ideal for bulk mail. Redi-Seal envelopes have pressure-activated latex adhesive on 2 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 heavyweight 28 lb kraft paper—opaque to protect private contents and durable enough for lots of hard office tasks. Center seams give added strength for heavy contents. Our large envelope can store letter-sized papers flat without ugly folds and creases. This classic open-end envelope is ideal for mailing manuscripts, homeschool packets, workbooks, sales literature, newsletters or contracts. Mail heavy enclosures with confidence. Stock up on boxes for your next bulk mail project!