Tamper evident bags

Selecting the appropriate security level depends on the value of the contents. For high-value items like cash or confidential documents, prioritize bags with Level 4 or Level 5 security features, which include void-evident heat and cold indicators, chemical-reactive inks, and micro-printed edges to prevent side-cutting and resealing. For standard retail or clinical samples, a Level 2 adhesive closure that shows physical distortion upon opening is usually sufficient.

Ensure the bags are made from High-Density Polyethylene (HDPE) or Co-extruded LDPE with a thickness of at least 50-70 microns to prevent punctures and tears. For international shipping, verify compliance with ICAO and IATA standards (especially for STEBs used in duty-free) and ensure the materials are 100% recyclable to meet global sustainability regulations.

To ensure a robust chain of custody, bags must feature unique sequential numbering and matching barcodes (1D or QR codes) on both the bag body and the tear-off receipt. Buyers should also request custom branding and surface-writable panels that allow for easy labeling with permanent markers without smudging, which is critical for logistics and forensic evidence handling.

Request the supplier to provide test reports demonstrating the seal's performance under extreme conditions. A high-quality seal should show a 'VOID' message or structural deformation when exposed to extreme heat (above 60°C), extreme cold (using Freon or dry ice), or solvent-based chemical attacks. Always ask for pre-production samples to conduct manual 'peel and pull' tests.

The biggest risk is 'Security Failure', where the adhesive fails to show tampering due to poor chemical formulation. To mitigate this, only source from manufacturers with ISO 9001 and ISO 17712 certifications. Another risk is batch inconsistency; ensure your contract includes a clause for third-party pre-shipment inspection to verify that the sequential numbering is not duplicated across the lot.

Focus on Total Cost of Ownership (TCO) rather than just the unit price. Negotiate for tiered pricing where the unit cost drops by 15-25% for orders exceeding 50,000 units. Additionally, request free plate-making for custom printing on long-term contracts and ask for flexible lead times (typically 15-21 days) to maintain a lean inventory.

Use Trade Assurance services on Made-in-China.com to protect your payment until the goods are verified. For shipping, choose Sea Freight (LCL/FCL) for bulk orders to reduce costs, but ensure the outer cartons are double-walled and palletized to prevent the security bags from being compressed or damaged during transit, which could accidentally trigger the tamper-evident features.