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Material guide

A plain-language guide to the materials behind our lids, cards, sheets, rollstock, pouches, and bags. It covers what each material is, how the options differ, and what to ask before you choose.

Last updated Sep 27, 2026

This guide explains terms, not test results. It gives no performance numbers, because performance depends on your device, your package design, and your process. Nominal values are on each product's spec sheet, and we can send the manufacturer's technical data, with test methods, on request. For definitions of individual terms, see the glossary. For which methods suit which products, see the sterilization compatibility chart.

Tyvek® grades: 1073B vs 2FS

Tyvek® is a strong, breathable sheet material. Sterilant gas can pass through it, while it acts as a barrier to microorganisms. Medical packaging uses a few specific grades. We work with two as standard. If your spec calls for another, ask us.

1073B is the heaviest and strongest medical Tyvek® grade. Choose it for heavy or sharp devices, where puncture resistance matters most. Typical applications include orthopedic implants and surgical kits. Our coated Tyvek® die-cut lids are cut from heat-seal coated 1073B.

2FS is a lighter grade. It costs less and suits lighter devices and high-speed form-fill-seal lines.

We supply both grades as coated Tyvek® rollstock for rigid-tray lidding, blister lidding, and flexible pouch stock.

Property1073B2FS
Chosen forStrength and puncture resistanceLower cost; suited to form-fill-seal
Typical useHeavy or sharp devices, such as orthopedic implants and surgical kitsLighter devices and high-speed form-fill-seal

Coated vs uncoated Tyvek®

Uncoated Tyvek® will not heat-seal to a rigid tray on its own. It does seal to films that carry their own sealant layer, such as the PE in PET/PE, which is how most Tyvek® pouches and header bags are made. A heat-seal coating is a thin adhesive layer applied to one side. Under heat and pressure on a sealing machine, the coating bonds the Tyvek® to a rigid tray, a blister or a wider range of films. That is what turns a sheet into a tray lid.

Coatings can cover the whole surface or be applied in a pattern. A pattern coating leaves uncoated areas between the coated ones, so the web stays breathable and gas can still pass through. It also gives a clean, visible peel.

Uncoated Tyvek® is the porous web in most Tyvek® and film pouches and in many header bags, where the film carries the sealant. It is also used unsealed, for loose sheets, interleaves, and components placed inside a package. Our uncoated Tyvek® sheets are cut in our cleanroom in custom shapes.

Medical paper, coated paper, and cold-seal paper

Paper is a porous, printable, and economical sterile barrier material. We supply three types as rollstock.

Medical grade, on this site, means the material maker supplies and controls the material for medical packaging under its quality system, with ISO 11607-1 material statements, and EN 868 declarations for paper, available on request.

Medical-grade sterilization paper is 100% cellulose. Some grades are made for steam. Others are optimized for EtO and gamma. It acts as a microbial barrier once sealed, heat-seals to the sealant layer of films such as PET/PE, and is free of optical brighteners.

Coated medical-grade paper comes with a heat-seal coating so it can seal to trays, films, and blisters. The coating can be applied in three ways:

  • Grid: a crosshatch of coated lines, with open areas between them
  • Allover: a continuous coating across the surface
  • Pattern: coating applied in a defined design

The coating is designed to let the paper peel cleanly from the tray or film, with minimal fiber tear when sealed within the right window.

Cold-seal paper carries a cohesive coating that seals to itself under pressure, with no heat. It suits products such as gloves, dressings, and syringes. The coating is not made with natural rubber latex.

HDPE vs LDPE film, and rigid HDPE cards

HDPE (high-density polyethylene) and LDPE (low-density polyethylene) are both forms of polyethylene. HDPE is stiffer. LDPE is softer and more flexible. We offer medical-grade HDPE/LDPE film for flexible parts and webs. On this site, “HDPE/LDPE film” means a coextruded blend of HDPE and LDPE.

Film thickness is given in µm (micrometers) or mil (thousandths of an inch). Our film runs 28–60 µm (≈1.1–2.4 mil). Header bags use a heavy-duty LDPE film for bulky or heavy devices and kits, with a porous header strip that lets sterilant in and out.

Film is not porous. It works with gamma and e-beam. For EtO, film parts go inside a package with a porous side, such as a Tyvek® or paper pouch or lid, and a film web is paired with a porous web, so the gas can get in and out.

Rigid HDPE cards are a different product. They are sheets of 100% virgin HDPE, 10–35 mil (0.25–0.89 mm) thick. They are much thicker than film, and they hold their shape. A card sits inside a chevron pouch or rigid tray to hold and protect the device.

PropertyFlexible filmRigid cards
ProductHDPE/LDPE film die-cut components and HDPE/LDPE film rollstockHDPE mounting and insert cards
FormFlexible film: die-cut parts or rollsRigid sheet: pre-cut shapes or rollstock on plastic cores
Thickness28–60 µm (≈1.1–2.4 mil)10–35 mil (0.25–0.89 mm)
Typical useLiners, protective layers, interleaves; pouch and bag making; form-fill-seal websHolding and protecting a device in a chevron pouch or rigid tray
Made in-house or suppliedDie-cut components: cut in our cleanroom. Rollstock: suppliedCut in our cleanroom

Pouch films: PET/PE, PA/PE and foil laminate

Most pouch films are laminates: layers of different plastics bonded together. The notation lists the layers from outside to inside. The inner PE (polyethylene) layer is the sealant, which melts to form the seal.

LaminateLayersWhat it addsFound in
PET/PEPolyester and polyethyleneThe standard film: clear and economicalTyvek® chevron pouches and paper chevron pouches
PA/PENylon (polyamide) and polyethyleneHigher puncture resistanceTyvek® chevron pouches, as an option
Foil laminateIncludes an aluminum foil layerNear-total barrier to oxygen, moisture, and lightFoil chevron pouches

Foil is not gas-permeable. EtO cannot reach a device inside a sealed foil pouch, so for EtO the foil package needs a porous path, such as a header bag or breather patch. Foil pouches are typically radiation-sterilized. They suit sensitive devices, diagnostics, and reagents with long shelf-life needs.

Tray substrates: PETG, HDPE, HIPS, PP, and PVC

A rigid tray is thermoformed from a plastic sheet. Lids seal to the tray's flange. These are the common tray plastics:

  • PETG: a clear, tough amorphous polyester (glycol-modified PET)
  • HDPE: high-density polyethylene
  • HIPS: high-impact polystyrene
  • PP: polypropylene
  • PVC: polyvinyl chloride

Our coated Tyvek® lids carry a pattern heat-seal coating. Tell us your tray resin when you order. Polyolefin trays (HDPE and PP) are often the hardest to seal well, so run seal trials early. Seal performance still depends on the tray, the sealing equipment, and the settings you use. Validate the seal on your own tray and sealing equipment before you release a package.

Heat and sterilization limits by material

  • Tyvek®: compatible with EtO, gamma and e-beam. Ask us about steam before you design around it.
  • Polyethylene (HDPE, LDPE and PE sealant layers): ask us about steam before you design around it.
  • Medical paper: steam grades are available; ask us.
  • Aluminum foil laminates: radiation, or EtO only with a header bag or breather.

Confirm every material in your own validated cycle.

Questions to answer before you choose

  • How will you sterilize? Now, and any method you might move to later. EtO needs a porous side; radiation needs materials that tolerate the dose; steam narrows the choice, so ask us.
  • How heavy is the device, and does it have sharp points or edges? This decides between 1073B and 2FS, PET/PE and PA/PE film, and whether you need a card.
  • What will you seal on? A tray sealer, a pouch sealer or a form-fill-seal line decides between die-cut lids, pre-made pouches and rollstock.
  • What is the tray made of? The lid coating has to suit the tray resin.
  • Does the product need a moisture, oxygen or light barrier, and for how long? If so, look at foil, and plan how EtO will get in if you use it.
  • Who opens the package, and where? Gloved hands in an operating room need a tab or chevron that starts easily.
  • What must be printed? Lot, expiry and symbols may decide between a printed lid or pouch and a label.
  • How many do you need now, and at launch? Small first runs suit die-cut parts; a move to form-fill-seal changes the format and needs its own validation.

Still choosing?

Answer a few questions in the material selector to see which products fit your device and process. Or send an engineering question with your spec, tray or pouch type, and sterilization method, and we will help you narrow it down. You can also browse all products.

Still choosing?

Ask the people who make the parts.

Tell us about the device and process, and we'll recommend a material and send samples.