Product Sheet
Tamper-Evident Courier Envelope Tape
Security closure tape for poly mailers and courier envelopes, with custom messaging and colours.
Available on request
Tamper-Evident Release Films
Tamper-Evident Release Film for Poly Mailers and Courier Packaging
Tamper-evident release film developed for e-commerce and courier packaging, with custom messaging, colours and construction support for converters.
At a glance
- Tamper evidence
- Visible VOID transfer on removal attempt
- Custom message
- VOID, STOP, TAMPERED BAG or your own wording
- Material
- 100% recyclable low-density polyethylene (LDPE)
- Standard widths
- 27, 30, 35 and 45 mm
- Standard colours
- Red, blue
Overview
E-commerce packaging travels through more hands than it used to, and the seal is the only part of the parcel that can testify to what happened on the way. This film is supplied to poly-mailer and courier-envelope converters as the security closure in their own bag construction.
When the seal is interfered with, the evidence is visible on arrival — which supports the recipient, the seller and the carrier in establishing where a problem occurred rather than arguing about it.
Colours, messaging and construction are customised to the mailer you produce, and application support is available while the film is brought onto your line.
Performance benefits
Interference is visible on arrival
A tampered seal shows evidence the recipient can see without needing to know what the packaging is supposed to look like.
Built for e-commerce volume
Supplied to converters as a closure component for poly mailers and courier envelopes produced at volume.
Brand protection at the closure
Custom messaging and colours let the seal carry the brand rather than reading as generic packaging tape.
Supports dispute resolution
Visible evidence at the seal helps establish whether a parcel was interfered with in transit.
Recyclable closure
The film is recyclable low-density polyethylene, so it stays compatible with the mailer's own recycling stream.
Converter application support
Technical support during setup so the film applies cleanly on your bag-making line.
Available configurations
- Width
- 27 mm
- 30 mm
- 35 mm
- 45 mm
- Or to your requirement
- Colour
- Red
- Blue
- Custom colours to requirement
- Message
- VOID
- STOP
- TAMPERED BAG
- Custom wording and artwork
- Applications supported
- Poly mailers
- Courier envelopes
- E-commerce despatch bags
Applications
- E-commerce poly mailers
- Courier and despatch envelopes
- Returns and reverse-logistics packaging
- Retail fulfilment packaging
How it works
01
Applied at the closure
The film is integrated as the security closure of the mailer during bag manufacture.
02
Sealed at despatch
The sender closes the mailer, activating the seal.
03
Interference leaves evidence
An attempt to open and reseal the mailer reveals visible VOID evidence at the closure.
04
Checked on receipt
The recipient can see whether the seal was interfered with before the parcel arrived.
Heat-indicator demonstration
When applicable security constructions are exposed to heat, the indicator changes colour to create visible evidence of the attempt. If the seal is lifted, the layered construction reveals a permanent VOID message.
View the demonstrationThe material in application
Production and application photography of this construction. Nothing here is a mock-up.
Sealed. The closure reads as intact. 
Lifted. The VOID transfer stays on the mailer.
Technical specifications
Final suitability should be confirmed through technical discussion and application testing.
| Property | Value | Status |
|---|---|---|
| Tamper evidence | Visible VOID transfer on removal attempt | Standard |
| Custom message | VOID, STOP, TAMPERED BAG or your own wording | Custom |
| Heat indicator | Level 4 constructionsSpecified per application, not standard on every construction. | Available |
| Property | Value | Status |
|---|---|---|
| Material | 100% recyclable low-density polyethylene (LDPE) | Standard |
| Standard widths | 27, 30, 35 and 45 mm | Standard |
| Standard colours | Red, blue | Standard |
| Custom colours | Available | Custom |
| Printing | Up to eight-colour gravure | Standard |
| Core size and roll length | Confirmed against your bag-making line | On enquiry |
How to read these values
- Standard
- Supplied as standard for this product.
- Available
- Available as an option on applicable constructions.
- Custom
- Made to your specification.
- On enquiry
- Confirmed against your application rather than published as a universal figure.
Documents and downloads
Application Guide
Tamper-Evident Security Overview
How visible tamper evidence works and which construction suits which application.
Available on request
Frequently asked
Anything not covered here, ask the team directly — application questions are usually faster to answer than to document.
Ask a technical questionDo you supply finished poly mailers?
No. PROASP supplies the tamper-evident release film to converters who manufacture poly mailers and courier envelopes. The film becomes the security closure within your own bag construction.
Can the film carry our customer's branding?
Yes. Colours, messaging and surface graphics are customisable through eight-colour gravure, so the closure can carry brand identity rather than reading as generic tape.
What happens if someone opens and reseals the mailer?
The removal attempt reveals visible VOID evidence at the closure. Resealing does not reverse it, so the interference remains apparent when the parcel is inspected on arrival.
Will this run on our existing bag-making line?
Construction and liner are configured to your line, and application support is available during setup. Share your mailer construction, film gauge and line speed when you enquire.
Related solutions
Tamper-Evident Release Films
Security Bag Film
Integrate visible tamper evidence into your bag construction without compromising production efficiency.
View solutionTamper-Evident Release Films
Level 4 Heat-Sensitive Film
Everything Level 3 does, plus a heat indicator that turns from white to pink when the seal is warmed.
View solutionCustom Development
Custom and OEM Development
Define the substrate, release level, dimensions, security response and finished format around your application.
View solution
Discuss Poly Mailer and Courier Film for your application
Send your substrate, dimensions, operating conditions and estimated volume. The enquiry form arrives pre-filled with this product so you only need to describe the application.