Why Gauge Matters in Poly Bags: Thickness, Durability & Cost

When choosing poly bags for your operation, gauge — or thickness — plays a critical role in performance, cost, and suitability. Whether you're packaging bolts, food, or industrial materials, selecting the right gauge ensures that your product is protected without overspending or compromising quality. 

In this post, we’ll break down what “gauge” means, how it's measured, and how to pick the right thickness for your packaging needs.

What Is Gauge?

Gauge refers to the thickness of a poly film, typically measured in mils.

1 mil = 0.001 inches. 

At M Plastics, we work with gauges ranging from 0.75 mil (very thin) to over 6 mil (very thick), depending on product and application. 

Why Gauge Matters?

Choosing the right gauge impacts: 

✅ Durability – Thicker bags resist punctures and tears 

✅ Cost – Thicker film uses more resin, increasing price 

✅ Weight – Affects shipping, especially for bulk-packed goods 

✅ Flexibility – Thin bags conform to shapes better

✅ Regulatory Compliance – Some industries require a minimum thickness

Common Gauge Recommendations

Bag Type	Typical Gauge
Light-duty parts/liners	1.5–2 mil
Food packaging	1.5–3 mil
Heavy bolts/hardware	3–4 mil
Rock & sand bags	4–6 mil
Box liners (with liquids)	3–4 mil
Lightweight bags	~1 mil

These are just guidelines — the right gauge also depends on bag size, sealing method, handling, and transport conditions.

Blown Film and Gauge Control

At M Plastics, our blown film extrusion lines are calibrated for accurate gauge consistency across the web. We monitor thickness using micrometers and perform regular QC checks on film before converting it into bags or tubing. 

For custom orders, we can adjust gauge to your product’s protection level — avoiding overkill that increases costs or underperformance that leads to damaged goods. 

Final Thoughts: 

Using the right gauge is not just a technical detail — it’s a strategic decision that affects your bottom line. It’s about finding the balance between strength and economy, ensuring your poly packaging does the job without wasting material. 

Not sure what gauge you need? We’re here to help. Our team can guide you based on product weight, usage, sealing method, and handling requirements — whether you’re packing by hand or using high-speed automation. 

Let’s talk about your ideal gauge, and how M Plastics Inc. can deliver the right film for your needs.