If you are buying ESD shielding bags, specify four things up front: the failure mode you are protecting against (electrostatic discharge, moisture ingress, or both), the acceptance test method, the bag size and seal type, and the quantity plus any print.
Do not stop at the word "anti-static." In electronics packaging that one word covers at least three different material classes, and only one of them actually shields a component like a Faraday cage. This guide explains the three classes, which standards to cite, and the exact fields that turn a vague request into a clean RFQ.
The three material classes you are actually choosing between
Most ESD packaging confusion comes from using "anti-static" and "shielding" as synonyms. They describe different jobs.
| Material class | What it does | What it does not do | Typical use |
|---|---|---|---|
| Pink / low-charging polyethylene (antistatic) | Reduces charge generation on the film itself | Does not block an external electrostatic field | Non-sensitive mechanical parts, general handling inside an ESD-protected area |
| Metallized static shielding | Metallized layer creates a Faraday-cage effect that attenuates discharge energy from outside | Shielding performance depends on the specific structure and sealing discipline | ESD-sensitive PCBs, modules, semiconductors and assemblies |
| Aluminum foil moisture barrier | Low moisture-vapour transmission, used with desiccant and a humidity indicator card | Only holds the dry interior if the seal and desiccant quantity are correct | Moisture-sensitive (MSL-rated) devices packed per JEDEC J-STD-033 |
If your part is ESD-sensitive and moisture-sensitive, you usually need a foil shielding / moisture barrier structure that does both jobs. State that explicitly instead of assuming a shielding bag is moisture-tight.
Specify the failure mode first, then the test method
A supplier cannot choose the right structure until you name the failure mode you are trying to prevent. The failure mode also tells you which acceptance method to write into the specification.
If the failure mode is electrostatic discharge
Cite the packaging material requirements standard rather than only writing "ESD bag." The EOS/ESD Association standard ANSI/ESD S541 defines packaging properties for protecting electrostatic-discharge-sensitive items through production and transport; the ESDA notes IEC 61340-5-3 is technically equivalent.
For acceptance, tell the supplier which method you accept against and what threshold your quality plan requires:
- Surface resistance: ANSI/ESD STM11.11
- Discharge shielding: ANSI/ESD STM11.31
Do not assume every "shielding" bag passes the same number. Specify the method and your threshold so the quote includes the matching test report.
If the failure mode is moisture ingress
For moisture/reflow-sensitive surface-mount devices, the controlling document is IPC/JEDEC J-STD-033, which defines dry packaging: a moisture barrier bag with the correct desiccant quantity and a humidity indicator card inside, sealed so the interior stays dry.
Write two things into the spec:
- The MSL level of the device and the J-STD-033 dry-pack requirement
- WVTR acceptance per ASTM F1249 for the barrier structure
The humidity indicator card inside the sealed bag is the field check that the dry pack held — buyers usually specify the card as part of the pack, not as an afterthought.
The six fields that make a clean RFQ
Use this checklist when you send the request. Each field removes a round of back-and-forth.
- Protected product and failure mode: ESD, moisture, physical damage, or a combination
- Required material class: metallized shielding, foil moisture barrier, or both in one structure
- Acceptance standard and test method: e.g. ANSI/ESD S541, STM11.11, STM11.31, ASTM F1249
- Bag dimensions, seal type (zipper or heat seal), and desiccant / humidity indicator card if moisture-sensitive
- Print: logo plus ESD / ESDS warning markings, and print method (the foil and shielding line runs gravure)
- Monthly quantity and destination (destination only when it changes the material or compliance route)
This is the same discipline behind our other spec guides — for example, the courier bag spec guide shows how width, height and quantity are enough to start a quote, and the stand-up pouch spec sheet shows how barrier, seal and filling-line fit belong together.
What Foldveil confirms before quote or artwork
Foldveil's foil and shielding bags cover the metallized static shielding line and the aluminum foil high-barrier moisture line in one made-to-order family (model FV-PS-FSB).
Three things are deliberate:
- Performance values are not published as fixed numbers. Surface resistance, discharge shielding and WVTR are confirmed against your acceptance method with the applicable test report, not inferred from the product family.
- Certification and test-document scope is verified for the selected factory, material and production run, and the available document numbers are shared with the quote.
- Structures and sizes are built to your component spec; print runs by gravure with your logo and ESD warning markings.
That is the honest version of "ESD bag." You tell us the failure mode and acceptance method, and we hand back the structure, the test report and the documents with the quotation.
Send a spec, not just a product name
A request that says only "ESD bags" will bounce back as questions. A request that names the failure mode, the standard, the size, the seal, the print and the quantity can move straight to quotation.
Start your request on the RFQ page with the six fields above — or send the failure mode and acceptance method and we will work the rest of the spec with you.