Large Mailing Envelopes 13x18 - Heavyweight 28lb Kraft, Self Seal

In this review the Blue Summit Large Mailing Envelopes 13x18 are presented as a practical choice for anyone who needs to mail or store oversized documents without folding. The bottom line: these envelopes are best for offices, artists, and small businesses that need a durable, tear-resistant mailer that seals quickly and securely. The most convincing reason to buy is the combination of heavyweight 28lb kraft paper and a reliable peel-and-seal adhesive that holds items like manuscripts, certificates, and art prints safely in transit.

Key Features

• Heavyweight construction: The 28lb kraft paper offers superior resistance to tearing and punctures, protecting contents during handling and shipping.
• Self-seal adhesive: A peelaway paper strip reveals a strong adhesive so envelopes can be closed quickly without moisture or extra tape.
• Large capacity: The 13 x 17.7 in dimensions fit letter, legal and other large documents without folding, which prevents creasing or damage to prints.
• Paper load: Each envelope will securely hold up to about 60 sheets of standard thickness paper in a sturdy, single-layer kraft design.
• Versatile uses: The size and strength make these suitable for mailing, storing, and organizing manuscripts, posters, certificates, and art prints.

Who It's For

These large manila envelopes are ideal for small businesses, law offices, schools, print shops, and independent artists who need a no-fuss way to mail or archive oversized documents. They work well when mailing multiple-page packets, unframed prints, or legal papers that must stay flat.

Shoppers who need waterproof protection, padded cushioning for fragile items, or rigid box packaging should look elsewhere; these kraft mailers are sturdy but not padded or waterproof and are best suited to flat, nonbreakable contents.

Pros & Cons

Pros

• Durable 28lb kraft stock provides real tear and puncture resistance for mailed documents.
• Peel-and-seal adhesive is convenient and produces a secure closure without moisture.
• Generous 13 x 17.7 in size fits letter and legal documents flat, avoiding creases.
• Good value when buying in bulk for office filing and routine mailing needs.

Cons

• Not padded or water-resistant, so fragile or moisture-sensitive items may need additional protection.

Specifications

Material	28lb kraft paper
Dimensions	13 x 17.7 in
Capacity	Holds up to ~60 standard sheets
Closure type	Peel-and-seal adhesive strip
Pack quantity	50 mailers
Primary uses	Mailing, filing, storing oversized documents

Our Verdict

The Blue Summit Large Mailing Envelopes deliver solid protection and convenience for anyone sending or storing flat, nonfragile documents. With heavyweight 28lb kraft paper and an effective peel-and-seal adhesive, these envelopes are good value for offices and creatives who need to keep items flat and secure in transit, though buyers should add padding or waterproofing for delicate pieces.

Frequently Asked Questions

Will these fit legal-size documents?
Yes, the 13 x 17.7 in dimensions accommodate letter, legal and other oversized papers without folding.

Do they require moisture to seal?
No, the envelopes use a peelaway paper strip that reveals a pressure-sensitive adhesive, so no moisture is needed to close them.

Are these padded for fragile items?
No, they are single-layer kraft mailers and are not padded; add bubble wrap or use a padded mailer for fragile goods.