Mailing Envelopes

Paper and Tyvek mailing envelopes by the case, from 2.25 x 3.5 in to 24 x 36 in: kraft and white flat envelopes, clasp, Tyvek, expandable, jumbo and inter-department. Each row shows envelopes per case, the case price, the price per envelope and stock, with a button to add one case.

Kraft and white 28 lb paper envelopes
Size	Color and closure	Envelopes per case	Price per case	Price per envelope	Stock
6 x 9 in	Kraft, gummed flap	2,500	$430.20	17.2¢	In stock
6 x 9 in	Kraft, self-seal strip	500	$98.80	19.8¢	In stock
6 x 9 in	White, Redi-Seal	1,000	$360.32	36.0¢	In stock
6 x 9 in	White, self-seal strip	500	$93.60	18.7¢	In stock
6.5 x 9.5 in	Kraft, gummed flap	2,500	$439.62	17.6¢	In stock
6.5 x 9.5 in	White, Redi-Seal	1,000	$371.58	37.2¢	In stock
7.5 x 10.5 in	Kraft, Redi-Seal	1,000	$328.21	32.8¢	In stock
9 x 12 in	Kraft, gummed flap	1,000	$231.66	23.2¢	In stock
9 x 12 in	Kraft, self-seal strip	500	$124.54	24.9¢	In stock
9 x 12 in	White, Redi-Seal	500	$197.60	39.5¢	In stock
9.5 x 12.5 in	Kraft, gummed flap	500	$142.91	28.6¢	In stock
9.5 x 12.5 in	Kraft, Redi-Seal	500	$198.80	39.8¢	In stock
9.5 x 12.5 in	White, self-seal strip	500	$133.90	26.8¢	In stock
10 x 13 in	Kraft, self-seal strip	500	$208.75	41.8¢	In stock
10 x 15 in	Kraft, Redi-Seal	250	$167.28	66.9¢	In stock
11.5 x 14.5 in	Kraft, gummed flap	250	$120.55	48.2¢	In stock
12 x 15.5 in	Kraft, gummed flap	250	$109.23	43.7¢	In stock
12 x 15.5 in	Kraft, Redi-Seal	500	$342.55	68.5¢	In stock
12 x 15.5 in	White, self-seal strip	500	$197.60	39.5¢	In stock

28 lb kraft clasp envelopes, metal clasp with gummed flap
Size	Envelopes per case	Price per case	Price per envelope	Stock
4 x 6.375 in	1,000	$387.61	38.8¢	In stock
6.5 x 9.5 in	1,000	$246.13	24.6¢	In stock
9 x 12 in	500	$127.50	25.5¢	In stock
9.25 x 14.5 in	500	$260.47	52.1¢	In stock
9.5 x 12.5 in	500	$164.45	32.9¢	In stock
10 x 12 in	500	$211.42	42.3¢	In stock
10 x 13 in	500	$152.43	30.5¢	In stock
10 x 15 in	500	$204.97	41.0¢	In stock
11.5 x 14.5 in	500	$235.95	47.2¢	In stock
12 x 15.5 in	500	$230.20	46.0¢	In stock

14 lb Tyvek envelopes, flat, self-seal
Size	Color or print	Envelopes per case	Price per case	Price per envelope	Stock
6 x 9 in	White	100	$42.86	42.9¢	In stock
7.5 x 10.5 in	White	100	$50.34	50.3¢	In stock
9 x 12 in	White	100	$54.44	54.4¢	In stock
9 x 12 in	White, First Class print	100	$56.76	56.8¢	In stock
9 x 12 in	White, tamper evident	100	$116.48	$1.16	In stock
9 x 12 in	Black	100	$135.53	$1.36	In stock
9 x 12 in	Green	100	$135.53	$1.36	In stock
9 x 12 in	Red	100	$135.53	$1.36	In stock
9 x 12 in	Silver	100	$135.53	$1.36	In stock
9 x 12 in	Yellow	100	$135.53	$1.36	In stock
9.5 x 12.5 in	White	100	$60.23	60.2¢	In stock
10 x 13 in	White	100	$56.02	56.0¢	In stock
10 x 13 in	White, First Class print	100	$62.54	62.5¢	In stock
10 x 13 in	White, tamper evident	100	$122.08	$1.22	In stock
10 x 13 in	Black	100	$142.47	$1.42	In stock
10 x 13 in	Green	100	$142.47	$1.42	In stock
10 x 13 in	Red	100	$142.47	$1.42	In stock
10 x 13 in	Silver	100	$142.47	$1.42	In stock
10 x 13 in	Yellow	100	$142.47	$1.42	In stock
10 x 15 in	White	100	$72.97	73.0¢	In stock
12 x 15.5 in	White	100	$79.30	79.3¢	In stock
12 x 15.5 in	Black	100	$178.37	$1.78	In stock
12 x 15.5 in	Green	100	$178.37	$1.78	In stock
12 x 15.5 in	Red	100	$178.37	$1.78	In stock
12 x 15.5 in	Silver	100	$178.37	$1.78	In stock
12 x 15.5 in	Yellow	100	$178.37	$1.78	In stock
13 x 19 in	White	100	$163.05	$1.63	In stock
15 x 20 in	White	100	$254.64	$2.55	In stock

Expandable envelopes with a gusset, self-seal
Size with expansion	Material	Envelopes per case	Price per case	Price per envelope	Stock
5 x 11 x 2 in	Kraft, 40 lb paper	100	$64.10	64.1¢	In stock
9 x 12 x 2 in	Kraft, 40 lb paper	250	$201.31	80.5¢	In stock
9 x 12 x 2 in	White Tyvek, 18 lb	100	$122.41	$1.22	In stock
9.5 x 13 x 2 in	Kraft, 40 lb paper	250	$210.94	84.4¢	In stock
10 x 12 x 2 in	Kraft, 40 lb paper	100	$94.16	94.2¢	In stock
10 x 13 x 1.5 in	White Tyvek, 18 lb	100	$115.01	$1.15	In stock
10 x 13 x 1.5 in	White Tyvek, First Class print	100	$125.78	$1.26	In stock
10 x 13 x 2 in	Kraft, 40 lb paper	100	$96.20	96.2¢	In stock
10 x 13 x 2 in	White Tyvek, 18 lb	100	$136.24	$1.36	In stock
10 x 15 x 2 in	White Tyvek, 18 lb	100	$153.58	$1.54	In stock
12 x 15 x 3 in	Kraft, 40 lb paper	250	$314.04	$1.26	In stock
12 x 16 x 2 in	White Tyvek, 18 lb	100	$172.54	$1.73	In stock
12 x 16 x 2 in	White Tyvek, First Class print	100	$187.12	$1.87	In stock
12 x 16 x 4 in	White Tyvek, 18 lb	50	$126.59	$2.53	In stock

28 lb jumbo envelopes, ungummed flap
Size	Color	Envelopes per case	Price per case	Price per envelope	Stock
12.5 x 18.5 in	Kraft	100	$50.79	50.8¢	In stock
12.5 x 18.5 in	White	250	$137.80	55.1¢	In stock
14 x 18 in	Kraft	100	$58.28	58.3¢	In stock
15 x 20 in	Kraft	100	$67.18	67.2¢	In stock
15 x 20 in	White	250	$173.71	69.5¢	In stock
16 x 20 in	Kraft	100	$72.86	72.9¢	In stock
17 x 22 in	Kraft	100	$71.54	71.5¢	In stock
17 x 22 in	White	250	$209.30	83.7¢	In stock
18 x 23 in	Kraft	100	$90.78	90.8¢	In stock
22 x 27 in	Kraft	100	$109.20	$1.09	In stock
22 x 27 in	White	100	$125.45	$1.25	In stock
24 x 36 in	Kraft	100	$257.83	$2.58	In stock

Small kraft, #10 business and inter-department envelopes
Size	Type	Envelopes per case	Price per case	Price per envelope	Stock
2.25 x 3.5 in	Kraft, gummed flap	5,000	$356.63	7.1¢	In stock
2.5 x 4.25 in	Kraft, gummed flap	5,000	$377.00	7.5¢	In stock
3.125 x 5.5 in	Kraft, gummed flap	5,000	$509.38	10.2¢	In stock
3.375 x 6 in	Kraft, gummed flap	5,000	$592.80	11.9¢	In stock
3.5 x 6.5 in	Kraft, gummed flap	5,000	$673.62	13.5¢	In stock
4.125 x 9.5 in	#10 window, security tint, Redi-Seal	2,500	$407.94	16.3¢	In stock
10 x 13 in	Kraft, string and button	100	$56.52	56.5¢	In stock
10 x 13 in	Red, string and button	100	$110.54	$1.11	In stock
10 x 13 in	Yellow, string and button	100	$110.71	$1.11	In stock
10 x 13 in	Blue, string and button	100	$110.56	$1.11	In stock
10 x 15 in	Kraft, string and button	100	$91.48	91.5¢	In stock

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IN STOCK

Heavy-duty 12x10 kraft clasp envelopes built for reuse and durability. Reinforced metal clasps and secure gummed flap ensure documents stay protected during shipping. Each case includes 500 envelopes of 28 lb. woven kraft paper–the cost-effective solution for high-volume mailroom operations.

Envelopes & Mailers

12x10 28 lb Kraft Clasp Envelopes 500/Case

PN: EN1019

12 x 10 in 28 lb. Woven Paper 500 PER CASE

$211.42 / CASE

IN STOCK

These durable 9.5x12.5" kraft clasp envelopes feature reinforced metal clasps and a secure gummed flap for permanent sealing and multiple reuses. Made from sturdy 28 lb. woven paper to withstand frequent handling and shipping. Get 500 envelopes per case–the cost-effective solution for mailrooms and industrial operations.

Envelopes & Mailers

9 1/2 x 12 1/2" Kraft Clasp Envelopes Case of 500.

PN: EN1005

9 1/2 x 12 1/2 in 28 lb. Woven Paper 500 PER CASE

$164.45 / CASE

IN STOCK

Heavy-duty 28 lb. woven kraft clasp envelopes built for repeated use and secure sealing. Reinforced metal clasps withstand rough handling and multiple ship cycles. Dimensions 9.25" x 14.5", sold by the case (500 count)–the economical choice for high-volume mailrooms and industrial shipping.

Envelopes & Mailers

9.25x14.5 28 lb Kraft Clasp Envelopes 500/Case

PN: EN1018

9 1/4 x 14 1/2 in 28 lb. Woven Paper 500 PER CASE

$260.47 / CASE

IN STOCK

Heavy-duty 9x12" kraft clasp envelopes built from 28 lb. woven paper for maximum durability and reusability. Reinforced metal clasps and gummed flap provide a secure, permanent seal every time. Order a case of 500 and reduce your office envelope costs without compromising on strength or reliability.

Envelopes & Mailers

9x12 28 lb Kraft Clasp Envelopes 500/Case

PN: EN1004

9 x 12 in 28 lb. Woven Paper 500 PER CASE

$127.50 / CASE

IN STOCK

Heavy-duty 28 lb. woven kraft clasp envelopes sized 9.5 x 6.5" with reinforced metal clasps for secure, reusable storage and shipping. Gummed flap creates a permanent seal when moistened. Buy by the case (1000 count) and reduce per-unit costs for your mailroom or shipping department.

Envelopes & Mailers

9.5x6.5 28 lb Kraft Clasp Envelopes 1000/Case

PN: EN1002

9 1/2 x 6.5 in 28 lb. Woven Paper 1000 PER CASE

$246.13 / CASE

IN STOCK

Heavy-duty 6x9 kraft clasp envelopes with reinforced metal clasps for maximum reusability and cost savings. Made from durable 28 lb. woven paper with a gummed flap for a permanent seal. Each case contains 1000 envelopes–the mailroom standard for businesses shipping documents and packages securely.

Envelopes & Mailers

6x9 28 lb Kraft Clasp Envelopes 1000/Case

PN: EN1001

6 x 9 in 28 lb. Woven Paper 1000 PER CASE

$220.13 / CASE

IN STOCK

Heavy-duty 28 lb. woven kraft clasp envelopes with reinforced metal clasps for maximum reusability and cost savings. Secure gummed flap design ensures permanent seals for shipping compliance. Bulk case of 1,000 units sized 6 3/8" x 4" for mailroom and office packaging needs.

Envelopes & Mailers

6 3/8 x 4 in 28 lb Kraft Clasp Envelopes Reusable 1000/Case

PN: EN1014

6 3/8 x 4 in 28 lb. Woven Paper 1000 PER CASE

$387.61 / CASE

IN STOCK

Keep internal communications organized and secure with these 15x10" kraft inter-department envelopes. Featuring a reusable string-tie closure and pre-printed routing columns for Date, Deliver To, Department, Sent By, and Department–plus space for 31 entries. Sold by the case of 100 for maximum cost efficiency.

Envelopes & Mailers

15x10 Kraft String Closure Inter-Department Envelopes 100/Case

PN: EN1092

15 x 10 in 28 lb. Kraft Paper 100 PER CASE

$91.48 / CASE

IN STOCK

Keep internal company mail organized and compliant with these 10x13" kraft inter-department envelopes. Built from durable 28 lb. kraft paper with string-tie closure for repeated use, pre-printed with routing columns (Date, Deliver To, Department, Sent By, Department) and 52 entry spaces on both sides. Order by the case of 100 and reduce mailroom processing time.

Envelopes & Mailers

10x13 Kraft String Closure Inter-Department Envelopes 100/Case

PN: EN1093

10 x 13 in 28 lb. Kraft Paper 100 PER CASE

$56.52 / CASE

IN STOCK

Skip the moisture–just peel and seal. These 15x12x3 kraft expandable self-seal envelopes feature a tear-strip design that keeps adhesive dust-free and ready to ship. Durable 40 lb. paper stock handles bulky items with expanding sides. Case of 250 mailers saves time and cuts mailroom costs.

Envelopes & Mailers

15x12x3 Kraft Expandable Self-Seal Envelopes 250/Case

PN: EN1075

15 x 12 x 3 in 40 lb. Paper Stock 250 PER CASE

$314.04 / CASE

IN STOCK

10x13x2" Kraft Expandable Self-Seal Envelopes - Fast Peel & Seal, 100/Case

Envelopes & Mailers

10x13x2 Kraft Peel & Seal Expandable Self-Seal Envelopes 100/Case

PN: EN1076

10 x 13 x 2 in 40 lb. Paper Stock 100 PER CASE

$103.03 / CASE

IN STOCK

10x13x2" Kraft Expandable Self-Seal Envelopes - No Moisture Needed, Case of 100

Envelopes & Mailers

10x13x2 Kraft Expandable Self-Seal Envelopes 100/Case

PN: EN1065

10 x 13 x 2 in 40 lb. Paper Stock 100 PER CASE

$96.20 / CASE

IN STOCK

Speed up your mailroom with these 12 x 10 x 2" kraft expandable self-seal envelopes that require zero moisture–just peel and seal in seconds. Built from durable 40 lb. paper stock with expandable sides to handle bulky items safely. Each case contains 100 envelopes ready to ship.

Envelopes & Mailers

12x10x2 Kraft Expandable Self-Seal Envelopes 100/Case

PN: EN1066

12 x 10 x 2 in 40 lb. Paper Stock 100 PER CASE

$94.16 / CASE

IN STOCK

Skip the moisture–just peel and seal. These 9.5" x 13" x 2" kraft expandable self-seal envelopes feature 40 lb. durable paper stock with sides that expand for bulky items. End-loading design, 250 per case. Ready to ship.

Envelopes & Mailers

9.5x13x2 Kraft Expandable Self-Seal Envelopes 250/Case

PN: EN1073

9 1/2 x 13 x 2 in 40 lb. Paper Stock 250 PER CASE

$210.94 / CASE

IN STOCK

Speed up your mailroom operations with these 9x12x2 kraft expandable self-seal envelopes that require zero moisture–just peel and seal. Made from durable 40 lb. paper stock with tear-strip protection, these 250-count cases deliver cost-efficient bulk shipping without compromising durability. End-loading design expands to accommodate bulky items safely.

Envelopes & Mailers

9x12x2 Kraft Expandable Self-Seal Envelopes 250/Case

PN: EN1072

9 x 12 x 2 in 40 lb. Paper Stock 250 PER CASE

$201.31 / CASE

IN STOCK

Speed up your mailroom operations with these 11x5x2" kraft expandable self-seal envelopes. No moisture required–simply peel and seal in seconds. Constructed from durable 40 lb. paper stock with tear-strip protection to keep adhesive dust-free for extended shelf life. Sold as a case of 100.

Envelopes & Mailers

11x5x2 Kraft Peel & Seal Expandable Self-Seal Envelopes 100/Case

PN: EN1064

11 x 5 x 2 in 40 lb. Paper Stock 100 PER CASE

$64.10 / CASE

IN STOCK

Keep internal mail organized and routed efficiently with these 13" x 10" blue inter-department envelopes. String and button closure allows repeated use, while pre-printed columns for Date, Deliver To, Department, Sent By, and Department track up to 31 entries per envelope. Buy by the case of 100.

Envelopes & Mailers

13x10 Blue String Closure Inter-Department Envelopes 100/Case

PN: EN1097

13 x 10 in Paper Stock 100 PER CASE

$110.56 / CASE

IN STOCK

10x13" Yellow Inter-Department Envelopes String Closure - Case of 100

Envelopes & Mailers

10x13 Yellow String Closure Inter-Department Envelopes 100/Case

PN: EN1096

10 x 13 in Paper Stock 100 PER CASE

$110.71 / CASE

IN STOCK

Keep internal mail organized and routed efficiently with these red 10x13" inter-department envelopes. Pre-printed with 5 tracking columns (Date, Deliver To, Department, Sent By, Department) and durable string-tie closure for repeated use. Case of 100 envelopes.

Envelopes & Mailers

10x13 Red String Closure Inter-Department Envelopes 100/Case

PN: EN1095

10 x 13 in Paper Stock 100 PER CASE

$110.54 / CASE

How to choose mailing envelopes

Size

Sizes are short side by long side, in inches. A letter sheet folded in half measures 5.5 x 8.5 in and fits a 6 x 9. A flat 8.5 x 11 sheet fits a 9 x 12, and a 10 x 13 adds an inch each way for thicker stacks. Legal 8.5 x 14 sheets fit a 9.25 x 14.5 or a 10 x 15. For binders and kits, use an expandable envelope with a 1.5 to 4 in gusset.

Postage depends on size

USPS sorts mail by shape. An envelope up to 6-1/8 in high, 11-1/2 in long and 1/4 in thick mails as a letter. A larger one up to 12 x 15 in and 3/4 in thick mails as a large envelope, which USPS also calls a flat.

USPS letter and large envelope limits
Mail shape	Max height	Max length	Max thickness	Sizes on this page
Letter	6-1/8 in	11-1/2 in	1/4 in	6 x 9, #10 business, 4 x 6.375 clasp
Large envelope or flat	12 in	15 in	3/4 in	6.5 x 9.5 to 11.5 x 14.5, including 9 x 12, 10 x 13 and 10 x 15
Over the flat limit	over 12 in	over 15 in	over 3/4 in	12 x 15.5, 13 x 19, 15 x 20 and the jumbo sizes

The 12 x 15.5 in size is half an inch longer than the large envelope maximum. Expandable envelopes packed thicker than 3/4 in also go over it. USPS sets a 3.5 x 5 in minimum for mail, so the 2.25 x 3.5 to 3.375 x 6 kraft sizes are coin and parts envelopes.

Paper, Tyvek or expandable

The flat kraft and white envelopes, the clasp envelopes and the jumbo envelopes are 28 lb paper. The Tyvek flats are 14 lb DuPont Tyvek. Colored Tyvek comes in black, green, red, silver and yellow in 9 x 12, 10 x 13 and 12 x 15.5 in. The First Class versions carry a printed First Class border. Kraft expandable envelopes are 40 lb paper and the Tyvek expandables are 18 lb.

Closure

Gummed flap: moisten the gum and press it shut for a permanent seal.
Self-seal strip: peel the release strip and press. No water or tape.
Redi-Seal: press the flap down to seal. No moisture needed.
Metal clasp with gummed flap: close it with the clasp to open and reuse it, or moisten the gum to seal it for good.
String and button: the inter-department envelopes wind shut and open again.
Ungummed flap: the jumbo envelopes have no adhesive. Close them with tape.
Tamper evident: the 9 x 12 and 10 x 13 tamper evident Tyvek envelopes show OPENED in red once the seal is broken.

Buying by the case

Every price on this page is for one full case. Small kraft envelopes come 5,000 to a case, #10 business envelopes 2,500, flat paper envelopes 250 to 2,500, clasp envelopes 500 or 1,000, Tyvek flats 100, and jumbo envelopes 100 or 250.

Volume pricing comes off at checkout: 3% at 3 or more items in the cart and 5% at 6 or more. Orders of one or two items get free ground shipping in the US at $99 or more when the checkout shipping charge is $29.95 or less. Orders of one or two items with a product subtotal of $500 or more ship free when the checkout freight rate is $120 or less. Orders of three or more items get the volume discount instead of free shipping.

For pallet quantities, a standing order or a mix of sizes, send the SKUs, case counts and delivery ZIP on a bulk quote. The quote includes freight to your ZIP, and you can pay by card or ACH.

Request a bulk quote

Common questions

What are 9x12 envelopes called?

Catalog envelopes or large envelopes. A 9 x 12 holds a letter-size 8.5 x 11 sheet without folding. This page lists 9 x 12 in kraft and white paper, kraft clasp, Tyvek and expandable styles.

What are clasp envelopes?

Paper envelopes with a metal clasp and a gummed flap. The clasp holds the flap shut and opens again, so the envelope can be reused. Moisten the gum when you want a permanent seal. The clasp sizes in the table run from 4 x 6.375 to 12 x 15.5 in, all in 28 lb kraft.

Does USPS accept clasp envelopes?

Yes. For letter-size mail, USPS lists clasps, strings and buttons as nonmachinable features, and First-Class letters with them pay a nonmachinable surcharge. In the clasp table, only the 4 x 6.375 in size is letter size. The other nine sizes are large envelopes or bigger.

Are Tyvek envelopes waterproof?

The Tyvek listings describe the material as tear, puncture and moisture resistant, and several call it waterproof. For paper, the 9.5 x 12.5 kraft gummed listing says the paper is not treated for water resistance.

Which envelopes can be reused?

Clasp envelopes, string and button inter-department envelopes and the ungummed jumbo envelopes. Their listings describe reuse.

Letter and large envelope limits come from USPS Business Mail 101, Sizes for Large Envelopes and Flats and the USPS Quick Service Guide 201. Sizes, case counts, paper and Tyvek weights, closures, reuse and resistance notes come from the product listings.

Buying path

Buy Mailing Envelopes by the specs that change the order

Use filters, product titles, and product pages to compare size, material, pack count, case quantity, and fit before ordering.

Compare

Use filters and product titles to narrow by the specs that affect fit.

Confirm

Open the product page before ordering a case so you can check quantity, unit, and limits.

Reorder

Save the SKU or product link for repeat purchasing and support questions.

Larger orders

For pallet, recurring, or mixed-SKU orders, send your list and ZIP and get a delivered price by email.

What to check first

Usable inside size
Padding or material
Closure type
Case quantity

Common wrong-order risk: Forgetting item thickness. A mailer that fits flat dimensions can still be too tight once the product is packed.

Compare mailer vs box -> Get a delivered quote for larger orders -> Read the mailers guide -> View products below ->

Mailing Envelopes

How to choose mailing envelopes

Size

Postage depends on size

Paper, Tyvek or expandable

Closure

Buying by the case

Common questions

Related

Product Help Request

Buy Mailing Envelopes by the specs that change the order

What to check first