Every ton of recycled cardboard saves 17 treesReusing one box saves 3.5 kWh of energyCardboard can be recycled up to 7 timesWe have diverted over 2 million boxes from landfillsUsed boxes reduce carbon emissions by up to 60%One tree produces approximately 100 boxesPortland Boxes: 100% committed to zero-waste operationsChoosing used boxes saves up to 70% compared to newEvery ton of recycled cardboard saves 17 treesReusing one box saves 3.5 kWh of energyCardboard can be recycled up to 7 timesWe have diverted over 2 million boxes from landfillsUsed boxes reduce carbon emissions by up to 60%One tree produces approximately 100 boxesPortland Boxes: 100% committed to zero-waste operationsChoosing used boxes saves up to 70% compared to new
Portland Boxes
Single Wall

Single Wall Corrugated Boxes

The most versatile and cost-effective packaging option. One layer of fluting provides reliable protection for everyday shipping and storage.

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What is Single Wall Corrugated?

Single wall corrugated board consists of one layer of fluted medium sandwiched between two flat linerboard faces. This construction creates a lightweight yet sturdy material that provides excellent protection for a wide range of products.

The fluting acts as a cushion, absorbing impacts and vibrations during transit. The outer liners provide a smooth surface for printing and labeling while adding structural rigidity.

Single wall boxes are the most commonly used corrugated boxes in the world, making up approximately 80% of all corrugated packaging. Their popularity stems from their excellent balance of protection, weight, and cost.

B-Flute (3mm)

Fine fluting for excellent printing surface. Great for retail displays and lightweight items.

C-Flute (4mm)

The most common flute type. Good balance of cushioning and stacking strength for general shipping.

E-Flute (1.5mm)

Micro-flute for thin, lightweight packaging. Perfect for mailers and small product boxes.

Available Sizes & Specifications

Dimensions (L x W x H)ECT RatingMax WeightTypical Use
4 x 4 x 43210 lbsJewelry, small parts, samples
6 x 6 x 63220 lbsSmall items, candles, samples
8 x 8 x 83225 lbsCandles, jars, small electronics
10 x 8 x 63225 lbsBooks, DVDs, documents
12 x 10 x 83230 lbsRetail goods, craft supplies
12 x 12 x 123230 lbsKitchen items, toys
14 x 14 x 143235 lbsClothing bundles, light equipment
16 x 12 x 123235 lbsShoes, retail goods
16 x 16 x 164440 lbsMedium electronics, small appliances
18 x 14 x 124440 lbsOffice supplies, tools
18 x 18 x 164445 lbsMedium appliances, bulk items
18 x 18 x 244450 lbsMoving boxes, household items
20 x 20 x 204450 lbsLarge items, multiple products
24 x 18 x 184455 lbsLinens, pillows, bulky items
24 x 24 x 244460 lbsMoving, storage, large items
24 x 20 x 124450 lbsFlat items, trays, baking supplies
30 x 18 x 124445 lbsLong flat items, prints, frames
Flute Profiles

Detailed Flute Comparison

The flute profile determines how your single wall box performs. Each flute type offers a different balance of cushioning, stacking strength, printing quality, and material usage.

Flute TypeHeightFlutes/ftCushioningStackingPrint QualityBest Applications
A-Flute5mm (3/16")33-36ExcellentGoodFairFragile items, cushion-critical shipments
B-Flute3mm (1/8")47-52GoodVery GoodVery GoodRetail displays, canned goods, die-cut boxes
C-Flute4mm (5/32")39-43Very GoodVery GoodGoodGeneral shipping, most common all-purpose flute
E-Flute1.5mm (1/16")90-96FairGoodExcellentMailers, pizza boxes, lightweight retail packaging
F-Flute0.8mm (1/32")120+LimitedFairExcellentMicro-corrugated packaging, cosmetic boxes, jewelry

How Fluting Works

Fluting is the wavy layer sandwiched between the two flat liners of corrugated board. It works on the same principle as an arch bridge — the curved shape distributes force evenly across the structure. When a box is compressed from the top (stacking), the flutes bear the load vertically. When the box receives an impact from the side (dropping), the flutes act as springs, absorbing and distributing the energy across the entire wall rather than concentrating it at the impact point. This is why corrugated board can protect products from both compression and shock simultaneously.

Flute Direction Matters

In a standard RSC (Regular Slotted Container) box, the flutes run vertically when the box is standing upright. This is intentional — vertical flutes provide maximum stacking strength because the arches are aligned with the compressive force of gravity. If you see a box where the flutes run horizontally, it was either assembled incorrectly or designed for a specific application where side-impact cushioning is more important than stacking strength. When storing or stacking single wall boxes, always ensure the flute direction is vertical for maximum performance.

By Industry

Single Wall Applications by Industry

Single wall corrugated boxes serve nearly every industry. Here is how different sectors use them and which sizes and specifications work best for each.

E-Commerce & Online Retail

Sizes: 6x6x6 to 20x20x20ECT: 32-44

The backbone of online fulfillment. Single wall boxes handle 90%+ of e-commerce shipments under 50 lbs. Grade A used boxes are visually clean enough for customer-facing deliveries. Most sellers use 3-5 standard sizes to cover their entire product range.

Food & Beverage

Sizes: 10x8x6 to 18x18x16ECT: 32-44

Bakeries, coffee roasters, breweries, and specialty food producers ship products in single wall boxes daily. For non-direct-food-contact applications (boxed/wrapped products), used single wall is FDA-acceptable and costs 50% less than new.

Books & Media

Sizes: 10x8x6 to 14x14x14ECT: 32

Publishers, bookstores, and media distributors rely on single wall boxes for their excellent weight-to-volume ratio. Books are heavy for their size, and ECT 32 single wall handles the load while minimizing dimensional weight surcharges from carriers.

Apparel & Fashion

Sizes: 14x14x14 to 24x18x18ECT: 32

Clothing is lightweight and non-fragile, making single wall the ideal choice. Even Grade B and C boxes work well because the visual condition of the outer box matters less when products are individually poly-bagged inside.

Electronics (Light)

Sizes: 8x8x8 to 18x18x16ECT: 32-44

Consumer electronics under 30 lbs ship safely in single wall boxes with appropriate cushioning. Tablets, small printers, routers, and accessories all fit the single wall profile. ECT 44 recommended for items over $200 in value.

Health & Beauty

Sizes: 4x4x4 to 12x12x12ECT: 32

Cosmetics, supplements, and personal care brands use small single wall boxes for subscription fulfillment and direct-to-consumer shipping. Smaller flute profiles (E-flute) provide a premium feel while staying cost-effective.

Arts & Crafts

Sizes: 12x12x12 to 24x24x24ECT: 32-44

Artists, makers, and craft sellers protect paintings, ceramics, and handmade goods in single wall boxes with custom padding. The wide size range accommodates everything from small pottery to framed prints.

Office & Business Supplies

Sizes: 10x8x6 to 18x18x16ECT: 32

Office supply distributors, print shops, and business services use single wall boxes for reams of paper, toner cartridges, promotional materials, and office equipment under 40 lbs.

Agriculture & Nurseries

Sizes: 12x12x12 to 24x18x18ECT: 44

Plant nurseries, seed companies, and small farms ship live plants, bulbs, and produce in ventilated single wall boxes. ECT 44 is recommended for the moisture resistance and extra strength needed in agricultural applications.

Decision Guide

How to Choose the Right Single Wall Box

Follow this decision guide to select the optimal single wall box for your application. Consider these four factors in order.

1

Determine the Size

Measure your product at its widest, tallest, and deepest points. Add 2 inches to each dimension for cushioning material. If shipping multiple items in one box, lay them out in the most space-efficient configuration and measure the combined footprint. Oversizing wastes material and increases dimensional weight charges; undersizing risks damage. The goal is a snug fit with consistent cushioning on all six faces.

2

Select the ECT Rating

For items under 30 lbs, ECT 32 provides more than enough strength. For items 30-65 lbs, step up to ECT 44 for the additional crush resistance. If your product has sharp edges or concentrated weight points, choose one ECT rating higher than the weight alone would suggest. If boxes will be stacked (palletized shipping or warehouse storage), ECT 44 is recommended regardless of individual box weight because the bottom boxes bear the combined load of all boxes above.

3

Choose the Flute Profile

C-Flute is the safe default for general shipping — it offers the best all-around balance of cushioning, stacking strength, and cost. Choose B-Flute if you need a better printing surface (retail-facing boxes) or a thinner profile (fitting into tight shipping configurations). Choose E-Flute for lightweight mailers and premium retail packaging where a thinner, more refined look is desired. A-Flute is rarely used in standard shipping but is ideal for maximum cushioning of highly fragile items.

4

Select the Condition Grade

Grade A (Like New) for customer-facing shipments where appearance matters. Grade B (Good) for standard e-commerce and business shipping where minor cosmetic imperfections are acceptable. Grade C (Fair) for warehouse storage, internal transfers, and cost-sensitive applications. Grade D (Used) for non-shipping uses like storage, organization, and packing material. Each step down in grade saves approximately 25-35% on cost with minimal impact on structural performance.

Single Wall Performance Data

Lab-tested performance metrics for our single wall corrugated boxes. All values represent minimum performance for used boxes in Grade A-B condition.

Performance MetricECT 32ECT 44Test Method
Edge Crush Test (ECT)32 lb/in (min)44 lb/in (min)TAPPI T 811
Burst Strength200 lb/in²275 lb/in²TAPPI T 810 (Mullen)
Flat Crush Test35 lb/in²50 lb/in²TAPPI T 825
Puncture Resistance30 in-oz45 in-ozTAPPI T 803
Box Compression (12x12x12)~600 lbs~900 lbsTAPPI T 804
Box Compression (24x24x24)~400 lbs~650 lbsTAPPI T 804
Moisture Absorption (24 hr)<15% by weight<12% by weightTAPPI T 412
Retention After 1 Use Cycle92-100% of original92-100% of originalInternal testing

Performance values are minimums for Grade A-B used boxes. Grade C-D boxes may show 10-25% reduction in compression and burst metrics. All tests conducted on samples from our warehouse inventory.

Order Single Wall Boxes Today

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