How to Select Pre-Opened Bags

Summarize this post:

Select pre-opened bags by defining the packed product and packaging process first. Dimensions, weight, edges, visibility, protective function, loading, sealing and equipment determine the required size, material, thickness, perforation and roll configuration.

Available Size Reference

These verified producible examples are not fixed limits. Custom dimensions are developed from product and process requirements.

3 × 4 in
76 × 102 mm

4 × 6 in
102 × 152 mm

4 × 8 in
102 × 203 mm

5 × 7 in
127 × 178 mm

5 × 8 in
127 × 203 mm

6 × 8 in
152 × 203 mm

6 × 10 in
152 × 254 mm

8 × 10 in
203 × 254 mm

8 × 12 in
203 × 305 mm

10 × 12 in
254 × 305 mm

10 × 15 in
254 × 381 mm

Thickness Guide

Mil	Approximate metric thickness
1.5 mil	38 μm
2 mil	51 μm
3 mil	76 μm
4 mil	102 μm

The family thickness reference is 0.03–0.10 mm. Product-specific values take priority, and final thickness must be confirmed for weight, edges, handling, feeding and sealing.

Construction & Roll Configuration

Specify width, length, opening orientation, bottom seal, perforation, tear-off direction, index length, core, quantity per roll, winding, unwind direction and maximum roll diameter. Vent-hole position and pattern must be defined where venting is required.

Product Type Comparison

Clear

Visual inspection

White Opaque

Content concealment

Clear Front / White Back

Visibility with rear contrast

Anti-Static

Defined static-control projects

ESD Protective

Documented ESD requirements

VCI

Metal corrosion-protection projects

Vented

Controlled air release

Custom Printed

Identification and presentation

Materials

LDPE is available where applicable. Standard clear or opaque film must not be assumed to provide anti-static, ESD or corrosion protection; each functional requirement needs its own acceptance criteria.

Printing & Customization

Custom gravure printing up to 14 colors is available for appropriate specifications. Provide artwork, dimensions, print coverage, orientation, registration and quantity.

Automation / Machine Selection

Match the opening, perforation, index length, roll/core configuration, unwind direction and sealing method to the equipment. Provide the packaging machine/model or technical drawings. Universal machine compatibility is not assumed.

Applications

Pre-opened bags can support suitable automated packing of hardware, electronic accessories, parts kits and other industrial components. Product geometry, pack count, protection and handling conditions determine the final specification.

How to Specify an Order

Maximum product width, length and depth
Packed quantity, total weight and edge condition
Bag size, material and thickness
Opening, perforation, venting and roll/core requirements
Printing artwork and orientation
Filling, sealing and equipment information

Ordering & Supply Information

MOQ	30,000 pieces
Lead Time	15–35 working days after design confirmation
Stock Samples	Free stock samples available
Custom Samples	Typically 7–10 working days
Trade Term	FOB Shenzhen
Shipping Port	Shenzhen / Guangzhou
Payment	30% deposit / 70% before shipment
Payment Methods	T/T / L/C / PayPal / Western Union
Packaging	Export carton boxes
Overall Supply Capacity	Up to 8,000,000 pieces per week

Frequently Asked Questions

What should be measured first?

Measure the maximum product envelope, packed weight and edge condition, then document loading and sealing requirements.

How is the correct bag size confirmed?

Allow for loading clearance, headspace, seal area and separation geometry, then validate the proposed size with the actual process.

When is venting needed?

Use venting only when trapped air affects filling, sealing or handling, and define the required hole position and pattern.

Can stock samples be requested?

Yes. Free stock samples are available; customized samples typically require 7–10 working days.

How to Select Pre-Opened Bags for Your Application

Available Size Reference

Thickness Guide

Construction & Roll Configuration