Are Compostable Courier Bags Strong Enough for Shipping?

Businesses across New Zealand are switching to eco-friendly packaging, but one common concern remains: are compostable courier bags strong enough for shipping? In this blog, we explore the durability, performance, and practicality of compostable bags in real-world shipping scenarios. We’ll also share tips for choosing the right type and size to ensure your goods arrive safely, sustainably, and professionally.

The Strength Behind Compostable Courier Bags

Many assume compostable materials are weak or fragile, but this couldn't be further from the truth. High-quality compostable courier bags are engineered from advanced bioplastics like PLA (polylactic acid), PBAT (polybutylene adipate terephthalate), and cornstarch-based polymers. These materials are:

• Tear-resistant

• Water-resistant

• Flexible and lightweight

• Designed to protect during transit

Most compostable bags used in shipping are tested under commercial conditions to meet durability standards. With proper use, they are just as reliable as conventional plastic bags for standard freight.

If you're also wondering about the reusability of these bags, we’ve got you covered. Check out our article: Can I Reuse Compostable Courier Bags? (And Other FAQs Answered), where we dive deeper into how these eco-friendly bags can be reused effectively without compromising sustainability.

Ideal Uses for Compostable Courier Bags

Compostable courier bags are best suited for:

• Clothing and soft goods

• Documents and flat items

• Boxed or pre-packaged products

They are not ideal for shipping heavy, sharp, or liquid items unless combined with protective inner packaging. Selecting the right bag size for your item is also essential to prevent stretching or tearing.

Want to learn how compostable courier bags can elevate your brand and make a stronger impression on customers? Check out our article: How Compostable Courier Bags Help Your Business Stand Out. It explains how packaging choices influence customer loyalty, brand perception, and environmental impact in the NZ market.

Are They Waterproof?

Compostable courier bags are water-resistant, meaning they can withstand rain, splashes, or brief exposure to moisture during transit. However, they aren’t fully waterproof like thick plastic mailers. For extra protection in wet conditions, businesses can:

• Use inner wrapping for sensitive goods

• Add compostable liners or sleeves

• Store packed orders in dry environments before pickup

Do They Hold Up in Long-Distance Shipping?

Yes—when used correctly. Compostable courier bags can perform well in domestic and international shipping scenarios, provided they aren’t overfilled or exposed to harsh weather for extended periods. The integrity of the bag depends on:

• Proper storage before packing

• Suitable item weight (usually up to 3–5kg depending on bag thickness)

• Minimal over-handling during freight

How Insinc Products Ensures Quality

At Insinc Products, we supply only certified, high-strength compostable courier bags designed to meet the needs of modern New Zealand businesses. Our bags are tested for performance, backed by certifications (AS 4736, EN 13432), and available in multiple sizes.

Whether you’re a local eCommerce brand or a large-scale distributor, we offer packaging solutions that combine reliability, sustainability, and brand appeal.

FAQ – Strength & Usage of Compostable Bags

Are compostable bags as strong as plastic ones?

They are comparably strong for light-to-medium-weight items. Plastic may outperform in extreme conditions, but compostable bags hold up well under typical courier use.

Will they tear during shipping?

Not if packed properly. Choose the right bag size, avoid sharp edges, and don’t overfill.

Can I use them for international deliveries?

Yes, they’re suitable for international use. Just ensure your carrier doesn’t expose them to extreme elements.

How much weight can compostable courier bags carry?

Most compostable bags can hold between 3–5kg, depending on their thickness and size.

Are compostable bags affected by weather?

Heat, sunlight, and humidity can weaken them over time. Store them properly and avoid long pre-shipment delays.

Conclusion

Compostable courier bags are a practical, planet-friendly option for most shipping needs. While not ideal for every product type, they provide excellent strength, flexibility, and moisture resistance for day-to-day eCommerce deliveries. With the right handling and supplier, you can ship with confidence—and conscience.