STM's EnCap™ process chemically bonds silver to every fiber, so the shield is the material — not a coating that cracks at the flex point, lifts at the seam or gives up in the environment. Engineered, converted and delivered from bulk roll to finished part by one U.S. engineering partner.
No cost · An engineer answers, not a form letter · Working under ITAR? Share only what you can.
Most shielding is an add-on — foil, mesh, sprays and surface-deposited coatings applied after the fact. On day one, every data sheet in this category has a good number.
You've probably lived at least one of these
Discovered at qualification, it's a redesign and a retest measured in months. Discovered in the field, it's a grounded asset, a recall, or a wall that has to come down. And the engineer who chose the material owns the failure.
Surface-deposited metal reaches the side of the fiber facing the source and stops there. EnCap™ bonds silver to every fiber, 100% — every filament, every side, all the way around. Approach against approach, no brands.
| Add-on shielding — foil, mesh, sprays, surface-deposited coatings | Built into the fiber — EnCap™ | |
|---|---|---|
| Where the metal sits | On the surface, on the side facing the source. | Chemically bonded to each fiber, all the way around. No shadow side. |
| At the flex point | Deposits crack and shed; conductivity drops with every cycle. | The base fabric keeps its stretch, drape, tear strength and recovery. The bond goes with it. |
| At the seam | Foil tears, tape lifts, the seam becomes a slot. | Conductive hook & loop carries current across the closure: 0.02 Ω·cm paired, rated to 5,000 cycles. |
| In the environment | Fluids, UV and thermal swings find every thin spot in a surface coating. | Characterized in-house from −100°F to 500°F, under UV accelerated aging and elevated-temperature fluid exposure. |
| In the weight budget | Metal, foil and fasteners buy dB with ounces. | −42 dB at 0.7 oz/yd² to −70 dB at 3.0 oz/yd² (ASTM D4935, 1 GHz). |
| Behind the wall | Foil is a vapor barrier: moisture, mold, remediation. | Breathable shielding — 814 g/m²/24 h water-vapor transmission on the non-woven. No vapor barrier. |
| Where it can go | Flat surfaces and rigid enclosures. | Composites and appliqués, garments and wearables, walls that still breathe, cases that fold. |
| What arrives | A roll — and a sourcing project across several vendors. | A roll, or a coated, laminated, absorber-integrated, die-cut part from one accountable partner. |
Approach-level comparison. Every STM figure is a data-sheet value or a published lab method; day-one and retained performance are documented on the EnCap™ page.
One engineering relationship covers the construction, the bond, the converting and the proof. This is what happens between your call and your drawing.
Knit, woven, non-woven, hook & loop or spandex. Silver, or nickel over silver. Base fabric, weight and width set for your frequencies, flex and environment — from the standard line or adjusted.
EnCap™ forms a chemical, molecular-level bond that encapsulates each fiber 100%. The fabric keeps its stretch, drape, tear strength and breathability; the conductivity becomes a property of the material.
Urethane, polyvinyl and silicone coatings. Pressure-sensitive, conductive and hot-melt lamination; carrier films. Absorbers integrated into tapes and appliqués. Slit, die-cut, CNC-cut, sewn or ultrasonically bonded to your drawing.
In-house electrical, mechanical, RF (30 MHz–1.5 GHz, 2–18 GHz) and environmental characterization to ASTM methods. An independent free-space shielding curve, 2–40 GHz, on every fabric data sheet. First-article support, full lot traceability, no substitutions.
We don't publish the chemistry. We publish the micrographs, the data sheets and the independent shielding curves.
Four applications, told at the altitude our customers' programs allow.
The situationA composite airframe with no metal skin to carry lightning current or ground the electronics, and no ounces to give back to foil and fasteners.
What STM deliveredA ground plane and lightning-strike path at fabric weight, integrated into the structure — and, as the program matured, a finished, coated, laminated appliqué. On the program for decades.
The situationA wearable or pressure-mapping sensor that has to stretch, breathe, touch skin — and read the same on patient 100,000 as on the prototype.
What STM deliveredHigh-purity silver bonded to a nylon/Lycra spandex, engineered for extended skin contact, with the bond built to hold resistivity through stretch and wear. (Data sheet SMS-0155.)
The situationHigh attenuation needed across the wall, the seams and the penetrations, an inspection coming, and foil's vapor barrier waiting to grow mold behind finished drywall.
What STM deliveredSwiftShield™ breathable woven and non-woven shielding, tested in a structure built to ICD/ICS-705 and IC Tech Spec v1.5.1 methods across 13 material configurations. Watch the mold time-lapse.
The situation5G densification flooding the rack, the shelter or the cell-site enclosure — and foil, cans and gasketing too heavy, rigid and slow to install at facility scale.
What STM deliveredLight, conformable conductive fabric in 36" to 76" rolls at 1.4–3.0 oz/yd² (ASTM D4935), cut, hung and wrapped on site as RF blankets, barriers, harness wraps and liners.
Filter the standard line by shielding effectiveness at 1 GHz, weight, stretch, coating, width and skin contact. Every value is a data-sheet value.
Most of the data that proves STM works belongs to the programs it protects. Here is the proof we own — and the place for the proof customers can give.
Lockheed Martin Elite Supplier, 11+ consecutive years — 100% quality and on-time delivery on that relationship, as scored by the most demanding customer in aerospace.
Method. NPB20NS, NPB20N3S and W077NS, all 36" wide, across 13 material configurations — measured pre-installation, after seam taping and after the second drywall layer. Nine antenna locations, two polarizations: 18 measurements per test cycle.
Also on the page: the mold-growth time-lapse, foil versus SwiftShield™, side by side.
Read the case study →Electrical, mechanical, RF and environmental characterization in-house, to ASTM methods. Every fabric data sheet carries an independent free-space shielding-effectiveness curve from 2 to 40 GHz.
Each one moves the program forward. The conversation with an engineer is what closes the gap.
The considerations our engineers walk through with every customer — breathability, conductivity, shielding, flex, abrasion, weight, width and skin contact — in one guide, with the standard line's data-sheet values side by side.
Instant download. No follow-up unless you ask for it.
The standard line, with data sheets and independent shielding curves. Tell us the application, frequency range, quantity horizon and timeline — an STM engineer reviews every request and, where useful, recommends a construction before the kit ships.
No cost. Reviewed by an engineer. Working under ITAR? Share only what you can.
Describe the application, the environment and the constraints — frequencies, weight budget, flex, exposure. An STM engineer responds within [X] business days. We support qualification through first article and deliver lot-traceable, U.S.-made material — the same in year ten as the lot you qualified.
An engineer answers, not a form letter. Straight answers on fit — if a gasket or an absorber serves you better, we'll say so.
EnCap™ is STM's proprietary metalization process. It forms a chemical, molecular-level bond between silver and the fiber, encapsulating each fiber 100% rather than depositing metal on the surface facing the source. The base fabric keeps its stretch, drape, tear strength and breathability, and the conductivity survives flex, abrasion and environmental exposure instead of cracking or shedding. We don't publish the chemistry; we publish the micrographs, the data sheets and the independent shielding curves.
Between −40 and −70 dB at 1 GHz (ASTM D4935) across the standard line, depending on construction and weight — from a 0.7 oz/yd² knit scrim at −42 dB to a 3.0 oz/yd² nickel/silver non-woven at −70 dB. Every fabric data sheet also carries an independent free-space shielding-effectiveness curve from 2 to 40 GHz. If your requirement sits outside the standard line, the construction, metal and weight can be adjusted.
Yes. All silver and nickel/silver STM products are manufactured in the USA at our Bloomfield, Connecticut facility. STM's materials meet Berry Amendment requirements for 100% domestic sourcing where the program requires it, and STM is ITAR and EAR compliant. Working under ITAR, share only what you're cleared to share; we'll work from the environment, frequencies and constraints. Our materials are dual-use and ship internationally under export license.
Both. STM manufactures bulk conductive fabric and also coats it (urethane, polyvinyl, silicone), laminates it (pressure-sensitive, conductive and hot-melt adhesives, carrier films), integrates absorbers and specialty coatings into tapes and appliqués, and slits, die-cuts and CNC-cuts to your drawing. Finished, value-added parts are now the largest share of what we ship.
No. STM supplies engineered conductive textiles and finished parts to companies, programs and institutions with a technical application. We don't sell consumer quantities or retail cuts.
All FAQs →
Day-one dB is the easy part. Bring the failure mode, the frequencies and the constraints, and get shielding that is a property of the material — from one U.S. partner, fiber to finished part.
No cost · An engineer answers, not a form letter · Working under ITAR? Share only what you can · Berry-compliant, U.S.-made