Boxes & Mailers

SELECTION EXPERT ADVICE

Wall Strength & Load Capacity
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Match single-, double-, or triple-wall corrugated construction to your product weight to prevent in-transit damage and minimize costly returns.
Dimensional Weight Cost Control
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Right-sized boxes cut carrier DIM weight charges, selecting the optimal LxWxH for each SKU directly lowers your per-shipment freight cost.
Mailer Box vs. RSC: Choose Correctly
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Self-locking mailer boxes suit branded DTC shipments; traditional RSC corrugated boxes are ideal for palletized B2B and high-volume fulfillment.

Need help choosing boxes?

Pick the right corrugated box without overpaying for size or strength

Use these buying guides to size your box, compare board strength, and avoid dimensional weight surcharges.

Corrugated Boxes Guide → How to choose size, strength, and wall type Box Size Calculator → Find the smallest safe box for your product 32 ECT vs 200 lb Test → Which board strength rating fits your shipment
Overview

3,094 corrugated boxes, literature mailers and mailing tubes from 2 to 36 inches, mostly ECT-32 kraft and white, sold in bundles of 10 to 50. Each listing shows inside dimensions, board grade and bundle count so you can match a carton to the part you ship. Orders ship from five US regional warehouses; for mixed or recurring orders use the bulk quote path with SKU, quantity and destination ZIP.

Related collections

IN STOCK Industrial-grade 20x16x8 corrugated shipping boxes built from ECT-32 kraft material for dependable protection and stackability. Pack of 25 boxes delivers volume savings ideal for warehouse managers and fulfillment operations. Recyclable kraft construction supports sustainable packaging goals.
Boxes - Corrugated

20x16x8 ECT-32 Kraft Corrugated Shipping Boxes 25-Pack

PN: 20168

20 x 16 x 8 in ECT-32 Single Wall Corrugated 25 PER BUNDLE
$63.49 / BUNDLE
IN STOCK 20x16x6 Kraft Corrugated Shipping Boxes, 500 Pack Pallet, 32 ECT
Boxes - Corrugated

20x16x6 ECT-32 Kraft Corrugated Shipping Boxes 25-Pack

PN: 20166

20 x 16 x 6 in ECT-32 Single Wall Corrugated 25 PER BUNDLE
$55.39 / BUNDLE
IN STOCK Heavy-duty ECT-44 single wall kraft corrugated boxes engineered for maximum stacking performance and impact protection. These 18x18x18" cartons deliver 40% greater strength than standard shipping containers, reducing damage claims and freight waste. Sold flat in bundles of 20 for space-efficient storage and fast deployment.
Boxes - Corrugated

18x18x18 ECT-44 Kraft Heavy-Duty Corrugated Shipping Boxes 20-Pack

PN: HD1818

18 x 18 x 18 in ECT-44 Single Wall Corrugated 20 PER BUNDLE
$92.73 / BUNDLE
IN STOCK ECT-32 single-wall corrugated boxes in clean white finish–5.3 cubic feet of dependable cube-shaped shipping capacity per box. Bundle of 20 offers maximum volume efficiency for warehouse fulfillment. Crisp white surface accepts printed labels and special instructions without compromise.
Boxes - Corrugated

18x18x18 ECT-32 White Corrugated Shipping Box Single Wall 20-Pack

PN: 181818W

18 x 18 x 18 in ECT-32 Single Wall Corrugated 20 PER BUNDLE
$96.67 / BUNDLE
IN STOCK Eliminate carton sizer equipment and reduce inventory complexity with these pre-scored ECT-32 kraft corrugated boxes. One SKU adjusts to multiple heights–fold to 18", 16", 14", or 12" to match your exact product size and cut parcel shipping costs. Sold as a bundle of 20 boxes.
Boxes - Corrugated

18x18x18 ECT-32 Multi-Depth Kraft Corrugated Shipping Boxes 20-Pack

PN: MD181818

18 x 18 x 18 in ECT-32 Single Wall Corrugated 20 PER BUNDLE
$67.59 / BUNDLE
IN STOCK 18x18x18 Kraft Corrugated Shipping Boxes, 380 Pack Pallet, 32 ECT
Boxes - Corrugated

18x18x18 ECT-32 Kraft Corrugated Shipping Boxes 20-Pack

PN: 181818

18 x 18 x 18 in ECT-32 Single Wall Corrugated 20 PER BUNDLE
$59.76 / BUNDLE
IN STOCK Engineered for demanding warehouse operations, these 18x18x12 heavy-duty corrugated boxes feature ECT-44 single wall kraft construction–40% stronger than standard shipping containers. Maximize stacking performance and freight efficiency with superior burst strength. Sold flat in bundles of 25 for space-saving storage and consistent supply.
Boxes - Corrugated

18x18x12 ECT-44 Kraft Heavy-Duty Corrugated Shipping Boxes 25-Pack

PN: HD181812

18 x 18 x 12 in ECT-44 Single Wall Corrugated 25 PER BUNDLE
$93.75 / BUNDLE
IN STOCK Heavy-duty ECT-48 kraft corrugated boxes deliver superior stacking strength and impact protection for demanding shipping and storage applications. These 18x18x10 double wall cartons are engineered for warehouse efficiency–bundle of 15 ships flat to maximize freight utilization and minimize storage footprint.
Boxes - Corrugated

18x18x10 ECT-48 Kraft Heavy-Duty Double Wall Corrugated Shipping Boxes 15-Pack

PN: HD181810DW

18 x 18 x 10 in ECT-48 Double Wall Corrugated 15 PER BUNDLE
$105.45 / BUNDLE
IN STOCK Industrial-grade 18x18x8 double wall corrugated boxes with ECT-48 kraft construction deliver maximum stacking strength and damage protection for high-volume shipping operations. Each bundle of 15 cartons ships flat to minimize storage footprint and reduce freight costs. Built for warehouse managers who demand reliable, heavy-duty packaging performance.
Boxes - Corrugated

18x18x8 ECT-48 Kraft Heavy Duty Double Wall Corrugated Shipping Boxes 15-Pack

PN: HD18188DW

18 x 18 x 8 in ECT-48 Double Wall Corrugated 15 PER BUNDLE
$64.72 / BUNDLE
IN STOCK 18x18x6 Kraft Double Wall Corrugated Boxes, 210 Pack Pallet, 48 ECT
Boxes - Corrugated

18x18x6 ECT-48 Kraft Double Wall Corrugated Boxes 15-Pack

PN: HD18186DW

18 x 18 x 6 in ECT-48 Double Wall Corrugated 15 PER BUNDLE
$80.97 / BUNDLE
IN STOCK ECT-32 kraft corrugated boxes sized 16" × 16" × 20"–built for mid-weight industrial shipping and storage. Sold in bundles of 20, these single-wall cartons deliver reliable protection and stackability at standard strength. Fully recyclable packaging.
Boxes - Corrugated

16x16x20 ECT-32 Kraft Corrugated Shipping Boxes 20-Pack

PN: 161620

16 x 16 x 20 in ECT-32 Single Wall Corrugated 20 PER BUNDLE
$65.05 / BUNDLE
IN STOCK Industry-standard 13x3x30 full overlap side loading boxes with ECT-32 single-wall corrugated construction. Ships and stores flat to maximize warehouse efficiency and reduce freight costs. Trusted by fulfillment directors nationwide–25-pack bundle ready to deploy.
Boxes - Corrugated

13x3x30 ECT-32 Full Overlap FOL Side Loading Boxes 25-Pack

PN: 13330FOL

13 x 3 x 30 in ECT-32 Single Wall Corrugated 25 PER BUNDLE
$103.04 / BUNDLE
IN STOCK End-load 12x12x24 tall corrugated boxes built from ECT-32 kraft material deliver reliable stacking strength and freight efficiency for irregular-shaped shipments. Holds 2.0 cubic feet per box. Sold as a bundle of 25 cartons ready to deploy in your warehouse operations.
Boxes - Corrugated

12x12x24 ECT-32 Kraft Corrugated Shipping Boxes 25-Pack

PN: 121224

12 x 12 x 24 in ECT-32 Single Wall Corrugated 25 PER BUNDLE
$60.57 / BUNDLE
IN STOCK Sturdy ECT-32 kraft corrugated boxes sized 6" × 6" × 30" for shipping tall items like trophies, shelving, and fishing rods. End-loading design speeds packing and sealing. Bundle of 25 boxes ships flat to maximize warehouse space efficiency.
Boxes - Corrugated

6x6x30 ECT-32 Kraft Corrugated Shipping Boxes 25-Pack

PN: 6630

6 x 6 x 30 in ECT-32 Single Wall Corrugated 25 PER BUNDLE
$51.96 / BUNDLE
IN STOCK Ship tall items with confidence using these 4x4x32 corrugated boxes made from sturdy ECT-32 kraft material. End-loading design speeds packing; sold flat in bundles of 25 for warehouse efficiency. Perfect replacement for mailing tubes when shipping shelving, fishing rods, trophies, and similar tall products.
Boxes - Corrugated

4x4x32 ECT-32 Kraft Corrugated Shipping Boxes 25-Pack

PN: 4432

4 x 4 x 32 in ECT-32 Single Wall Corrugated 25 PER BUNDLE
$64.60 / BUNDLE
IN STOCK Industrial-grade ECT-44 kraft side loading cartons designed for high-volume fulfillment operations. 30x6x24" dimensions with full overlap flaps deliver maximum edge protection and stacking strength. Ships flat in bundles of 10 to maximize warehouse efficiency and reduce freight costs.
Boxes - Corrugated

30x6x24 ECT-44 Kraft Side Loading Boxes 10-Pack

PN: HD30624FOL

30 x 6 x 24 in ECT-44 Corrugated 10 PER BUNDLE
$89.33 / BUNDLE

Product Help Request

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Buying path

Buy Boxes & Mailers 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

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Confirm

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Reorder

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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

  • Inside dimensions
  • Board grade or strength rating
  • Box style and closure
  • Case or bundle quantity
Common wrong-order risk: Choosing the outside size instead of the inside size. Confirm product fit, void fill, and storage space before ordering.
Use the box size finder -> Get a delivered quote for larger orders -> Compare corrugated box types -> View products below ->