The purchasing decision
TPU and PVC describe material families, not a complete dry bag specification. A buyer still needs to know the backing fabric, coating or laminate construction, thickness, finish and joining method. Two bags advertised with the same material name can differ in handle, flexibility and how the finished seams are made. Ask for a written material description tied to the proposed model.
Evaluate candidates with the same packed contents and handling sequence. Fold the closure, check the surface around welds and inspect how strap anchors meet the shell. If a supplier proposes a substitute material, request a fresh sample rather than assuming that a similar colour or texture means equivalent performance.
Cost comparisons should include the complete construction. A cheaper shell may come with different reinforcement, hardware or production tolerances. State which characteristics matter to the intended use and agree how those characteristics will be checked. Environmental or chemical-compliance statements should refer to identifiable documentation for the selected material and destination market.
What to compare before ordering
| Decision | Review with the supplier | Purpose |
|---|---|---|
| Material build | Backing, coating, thickness and finish. | Record a specific construction, not just TPU or PVC. |
| Sample behaviour | Fold, handle and inspect the finished shell. | Use the same evaluation sequence for both candidates. |
| Change control | Alternative material and supporting documents. | Reapprove substitutions before production. |
Include these details in your enquiry
- Proposed shell construction and thickness
- Surface finish and colour reference
- Joining method and reinforcement layout
- Required destination-market material documentation
Identify the model and the version of any drawing or artwork. Ask for assumptions, proposed changes, packing details and commercial terms to be shown in the quotation. MOQ, sample cost and production timing are confirmed for the agreed configuration.
Buyer questions
Does TPU automatically establish a waterproof rating?
No. A complete bag also includes seams, closures and attachments. Specify the assembled product and the intended test conditions.
Can I approve a material from a small swatch?
A swatch helps with colour and handle. It does not show how the selected material behaves in the finished closure, weld or strap attachment.
NEXT STEP
Turn the brief into a sample review.
Choose a product reference, mark the changes you need and send your expected quantities and destination market. Our Dongguan team can review the manufacturing options with you.
Discuss this project