Introduction
The closure is the last production detail and the first thing recipients touch. The right envelope closure balances security, convenience, cost and the unboxing experience — and different use cases genuinely need different closures.
This guide compares the five main envelope closure types used in production: gummed seal, self-seal (peel & seal), tear strip, velcro-style fastener, and double-sided tape. Each has a clear best-use case.
The Five Closures Compared
| Closure | How It Works | Security | Convenience | Cost | Best Use |
|---|---|---|---|---|---|
| Gummed (remoistenable) | Moisture-activated adhesive | Medium | Low (needs licking/water) | Lowest | Bulk business mail |
| Self-seal (peel & seal) | Release liner + pressure adhesive | Medium | High | Low+ | Everyday business, e-commerce |
| Tear strip (撕力线) | Perforated strip that tears to open | Medium | Medium | Medium | Documents, retail packaging |
| Velcro-style (摩丝扣) | Hook-and-loop flap fastener | Low–medium | High (reusable) | Medium | Reusable envelopes, premium |
| Double-sided tape (双面胶) | Tape strip under flap | Medium | High | Low+ | Bulk mailing, cross-border |
Closure Deep-Dives
1. Gummed Seal (Remoistenable)
The traditional closure: dried adhesive on the flap, activated by moisture. Still standard for high-volume business mail because it’s the cheapest per unit and processes well in automated machines.
- Pros: lowest cost, automation-friendly, no liner waste
- Cons: needs moisture to seal; recipient convenience matters for reply envelopes
- Best for: bulk business mail, invoices, statements
2. Self-Seal (Peel & Seal)
A pressure-sensitive adhesive strip covered by a release liner. Peel, press, done.
- Pros: instant seal, no moisture, reliable adhesion
- Cons: slightly higher cost than gum; liner adds waste
- Best for: the default choice for most business and e-commerce mail
3. Tear Strip (Perforated)
A perforated strip on the envelope that tears cleanly to open the flap — no scissors, no tearing the envelope.
- Pros: clean, tool-free opening; tamper-evident (once torn, visible)
- Cons: adds a production step; strip position must be exact
- Best for: documents, certificates, retail packaging where clean opening matters
4. Velcro-Style Fastener (Morse扣)
A hook-and-loop closure on the flap — press to close, pull to reopen. Reusable.
- Pros: reusable, premium feel, zero adhesive residue
- Cons: lower security (opens easily), higher cost
- Best for: reusable document envelopes, premium gifts, field-use pouches
5. Double-Sided Tape
A tape strip pre-applied under the flap — peel the backing, press the flap down.
- Pros: fast bulk sealing, strong bond, no moisture
- Cons: less premium feel; tape placement must be precise
- Best for: bulk mailing, cross-border shipments, automated sealing lines
Security Considerations
| Closure | Tamper Evidence |
|---|---|
| Gummed / self-seal | Low — resealable without obvious damage |
| Tear strip | Medium — tearing is visible |
| Velcro | Low — opens and closes freely |
| Security seal | High — fiber-tear or patterned break on opening |
For confidential mail (payroll, legal, medical), pair any closure with a security seal or security tint.
Choosing by Use Case
| Scenario | Recommended Closure |
|---|---|
| Invoices, statements | Gummed or self-seal |
| E-commerce packaging | Self-seal or double-sided tape |
| Certificates, legal documents | Tear strip (+ security seal for legal) |
| Reusable field envelopes | Velcro-style |
| Cross-border bulk | Double-sided tape or self-seal |
| Gift and premium | Velcro or tear strip with premium finish |
FAQ
What is the most common envelope closure?
Gummed (remoistenable) seal is the most common for bulk business mail; self-seal (peel & seal) is the most common for general and e-commerce use.
What is a tear strip envelope?
An envelope with a perforated strip that tears cleanly to open the flap — no scissors required, and the tear provides visible evidence of opening.
What is a velcro envelope closure?
A hook-and-loop fastener on the flap that lets the envelope open and close repeatedly — ideal for reusable document envelopes.
What is the strongest envelope seal?
Security seals (fiber-tear adhesive or patterned break) provide the strongest tamper evidence. Double-sided tape gives a strong physical bond for sealing.
Can I mix closures in one order?
Yes — closures are specified per product. Most factories produce multiple closure types in one order; see how to order custom envelopes.
Which closure is best for cross-border shipping?
Self-seal or double-sided tape — no moisture, strong bond, and reliable through temperature changes.