Self Sealing Poly Mailers
Ship smarter, seal faster, and protect every order — our self sealing poly mailers are built for businesses that move fast and demand reliability. No tape, no mess, no wasted time. Just peel, press, and ship.
Browse our full range of sizes, types, and custom options below
- Thickness: 2.0 – 4.0 Mil
- Sizes: 6×9" to 24×36" inch
- MOQ: 500 units
- Lead Time: 5–10 days
- We strictly keep all order details confidential without the customer's permission.
Why E-commerce Brands Choose Our Self Sealing Poly Mailers
Stop losing customers to seal failures and size mismatches
Seal Reliability
The 12-15mm reinforced adhesive strip bonds permanently within 45 seconds of application—verified through 10,000-cycle peel testing. Competitors typically offer 6-8mm strips that fail under humidity.
Temperature Resilience
Standard poly mailers become brittle at -10°C and lose adhesion above 45°C. Our formula maintains tack strength across the full -15°C to +60°C range, tested per ASTM D882 standards.
Dimensional Accuracy
With ±3% tolerance on all standard sizes, you receive consistent coverage without exposed edges or wasted material. We provide batch-specific test reports for orders over 10,000 units.
Dual Seal Technology | -15°C to +60°C
Built to perform where other mailers fail
12-15mm Reinforced Adhesive Strip
Our adhesive strip exceeds industry standards by 50%. The wider 12-15mm surface area distributes peel stress across a larger bonding zone, reducing failure rates by 34% compared to standard 8mm strips. Each strip undergoes inline QC inspection before lamination—no batch samples, 100% verification.
98.7% seal integrity after 72-hour cold exposure at -15°C.
72hr Waterproof Verification (ASTM D882)
Water damage during transit costs e-commerce brands an estimated 2-4% of packages in humid climates or during rainy seasons. Our mailers pass ASTM D882 waterproof verification with zero penetration after 72-hour submersion testing. The seamless construction has no stitched holes or weak points where moisture can enter.
3.15-5.51mil Thickness Options
Choose the right protection level for your products: 3.15-3.5mil: Lightweight apparel, soft goods, documents (most popular for fashion) 3.5-4.0mil: General merchandise, accessories, small electronics 4.0-5.51mil: Heavy items, sharp-edged products, industrial parts Thicker isn't always better—the optimal choice depends on your product weight and handling conditions.
Applications & Industries
Not sure which packaging is right for your products?
Primary Industries Served
| Industry | Application | Recommended Spec |
|---|---|---|
| Fashion & Apparel | 62% of our customers are DTC clothing brands | 3.15-3.5mil, 9×12″ to 12×15.5″ |
| Beauty & Cosmetics | Leak-proof formulas, lightweight shipping | 3.15mil, standard sizes |
| E-commerce Accessories | Jewelry, watches, phone cases | 3.15mil, 6×9″ to 9×12″ |
| Subscription Boxes | Curated products, branded unboxing | 3.5-4.0mil, custom sizes |
| Publishing | Books, magazines, educational materials | 3.15mil, 9×12″ to 10×13″ |
| Industrial Components | Replacement parts, hardware, tools | 4.0-5.51mil, custom sizes |
Poly Mailers vs Bubble Mailers vs Boxes
Not sure which packaging is right for your products?
| Criteria | Poly Mailers | Bubble Mailers | Boxes |
|---|---|---|---|
| Material Cost | $0.08-0.35/unit | $0.35-0.80/unit | $0.50-2.50/unit |
| Weight (empty) | 8-15g | 20-45g | 80-400g |
| Shipping Cost | Lowest (flats) | Medium | Highest (dimensional) |
| Protection Level | Basic to Medium | Medium | High |
| Best For | Apparel, soft goods, documents | Electronics under 2kg, fragile items | Items over 5kg, irregular shapes |
- When to choose poly mailers: Apparel, footwear (no hard boxes), documents, soft accessories, subscription boxes.
- When to choose bubble mailers: Electronics under 2kg, glass items, ceramics, anything requiring cushioned impact protection.
- When to choose boxes: Items over 5kg, products with irregular shapes, fragile items requiring rigid containment.
Size Selection Guide | ±3% Tolerance
Find the right fit without trial-and-error ordering
Standard Sizes (6×9" to 14×20")
| Size | Dimensions | Best For |
|---|---|---|
| SM | 6×9″ | Jewelry, accessories, small apparel |
| MD | 9×12″ | T-shirts, lightweight clothing, paperback books |
| LG | 10×13″ | Hoodies, folded garments, paperback sets |
| XL | 12×15.5″ | Multiple items, shoes (no box), linens |
| 2XL | 14×20″ | Bulk orders, larger apparel sets |
Custom Dimensions Available
Non-standard products require non-standard sizing. We produce custom dimensions from 4×6″ to 24×36″ with the same ±3% tolerance guarantee. MOQ for custom sizes starts at 5,000 units. Provide your product dimensions and we’ll calculate the optimal mailer size with 15% void space for secure closure.
Size Tolerance Test Report
Every batch ships with a certificate showing actual measured dimensions from random sampling. We test 50 units per 50,000 produced. If any unit exceeds ±3% tolerance, the entire batch is rejected and re-manufactured.
Specifications
Technical details at a glance
| Property | Specification |
|---|---|
| Material | Linear Low-Density Polyethylene (LLDPE) |
| Adhesive | Hot-melt pressure-sensitive, 12-15mm width |
| Thickness Range | 3.15-5.51mil (80-140 GSM equivalent) |
| Temperature Range | -15°C to +60°C operational |
| Water Resistance | 72hr verified per ASTM D882 |
| Tensile Strength | MD: 25-35 MPa, TD: 20-30 MPa |
| Elongation at Break | 400-600% |
| Seal Bond Time | 45 seconds (full bond) |
| Shelf Life | 18 months (sealed, original packaging) |
| Recyclability | #4 recyclable (where facilities available) |
| Size Tolerance | ±3% per batch test report |
Color Options & Customization
Make your unboxing moment memorable
Standard Colors (White/Black/Gray/Kraft)
White dominates e-commerce (reflects brand cleanliness), but black conveys premium positioning. Kraft appeals to eco-conscious brands. All standard colors ship within 7-10 business days.
Custom Pantone Colors
Match your brand exactly with Pantone-matched printing. We accept PMS or Pantone C codes.
- MOQ: 5,000 units
- Setup fee: Applies
- Extended lead time: 5-7 additional business days
Logo Printing & Functional Options
| Option | Description | MOQ |
|---|---|---|
| Logo placement | Single-side, double-side, or interior printed | 5,000 |
| Tamper-evident seals | +0.02/unit | No minimum |
| Resealable strips | +0.03/unit | No minimum |
| Perforated easy-open edges | +0.01/unit | No minimum |
| Anti-static formulation | +0.04/unit (for electronics) | 10,000 |
Factory Overview | ISO 9001:2015 Certified
Your packaging partner, not just a supplier
Production Capacity
- Daily output: 850,000 units
- Lead time: 12-18 business days (standard), 7-10 days (white/black in stock)
- Production lines: 12 automated lines + 2 custom/specialty lines
Quality Infrastructure
- ISO 9001:2015 certified since 2018
- In-house testing lab (peel strength, water resistance, temperature cycling)
- 50-point incoming material inspection
- 100% vision system inspection on adhesive application
Audit Support
- Sedex/SMETA audits available
- BSCI compliance documentation
- Factory walkthrough video available for verified buyers
Success Cases & Customer Reviews
What our customers report after switching
FAQ | Expert Answers
Answers to the questions we hear most from procurement managers
Q: What is the minimum order quantity (MOQ)?
A: Standard sizes start at 1,000 units. Custom dimensions require 5,000 minimum. Sample kits of 10 mixed units are available free (shipping only).
Q: How do I choose between 3.15mil and 5.51mil thickness?
A: For apparel, accessories, and documents under 2kg, 3.15-3.5mil is sufficient. For items with corners, heavy components, or items over 2kg, use 4.0-5.51mil. When in doubt, request a sample kit to test with your actual product.
Q: Can I get a sample before placing a bulk order?
A: Yes. We offer free sample kits (10 units, mixed standard sizes) and paid custom samples ($50-150 depending on specifications) before committing to production runs.
Q: What is your lead time for standard white/black mailers?
A: 7-10 business days for orders under 50,000 units. Standard colors in high demand are occasionally in stock for same-week shipment.
Q: Do your mailers work in high humidity environments?
A: Yes. The adhesive maintains bond strength up to 85% relative humidity. For tropical climates or monsoon seasons, we recommend the 4.0mil+ thickness for additional adhesive protection.
Q: Are your poly mailers recyclable?
A: Yes, they are made from #4 LLDPE plastic, which is recyclable where municipal recycling programs accept soft plastics. We also offer 30% recycled content options (post-consumer recycled) with slightly longer lead times.
Q: What print file formats do you accept?
A: We accept AI, EPS, PDF, and high-resolution PNG (300 DPI minimum). Our design team provides complimentary artwork review and one round of corrections included.
Q: Do you offer payment terms for large orders?
A: First orders are prepaid or 30% deposit, balance due before shipping. Established customers with approved credit can access Net-30 terms for orders over $10,000.
Q: Can I track my order production status?
A: Yes. Orders over 20,000 units receive weekly production updates with photos. All orders include tracking from production completion through shipment.
Q: What happens if a batch fails quality standards?
A: We reject and re-manufacture any batch that doesn’t meet specifications. We never ship substandard product. For documented quality issues, we provide full credit or replacement—no restocking fees.
Ready to eliminate seal failures and size mismatches from your supply chain?
Request a formal quote with your specifications. Response within 4 business hours.
RHK Packaging — ISO 9001:2015 Certified Manufacturer Since 2010
[email protected]