How to Extend the Life of Your Faraday Sleeve
What makes a Faraday sleeve work is its shielding fabric, a high-tech material that needs careful handling. The fabric's metallized layer blocks radio signals, but it doesn't cope well with water, heat or mechanical stress. Here's how to treat your sleeve so it lasts as long as possible.
Service Life vs. Warranty Period
Velter shielding products come with a six-month warranty. During that time, the sleeve retains its stated shielding performance, and if it stops blocking radio signals, you're covered by the warranty.
Service life is a different matter. It's how long a product keeps working when it's used correctly, and it doesn't end when the warranty does. A Faraday sleeve can keep working well beyond its warranty period. That said, shielding fabric is subject to wear and degradation, and depending on how intensively it's used, it will eventually lose its shielding properties.
From our experience
With heavy use, we consider six months the optimal service life for a sleeve. Throughout that period, the shielding fabric is guaranteed to keep its properties, provided all care guidelines are followed.
Improper use or extreme conditions shorten a sleeve's service life. Common culprits include regular contact with water, sharp objects inside the pocket, machine washing and ironing, and repeatedly folding the fabric in the same place. Harsh environments are a separate category of risk: sea salt, sand, solvents and road de-icing chemicals all attack the material.
All of these factors take a toll on the shielding performance of the metallized fabric layer.
What Affects Service Life
Follow these four simple rules to protect the shielding layer, and your Faraday sleeve will last as long as possible.
- Keep it dry.Polyester bags and sleeves are water-resistant but not waterproof, so don't submerge them or leave them in contact with water for long.
- Detach the sleeve before washing the bag.In our crossbody and sling bags, the shielding sleeve is removable, so unclip it before washing. You can also use it on its own as a standalone signal-blocking accessory.
- Keep other items out.Damp, dirty and sharp objects damage the inside of the sleeve, so keys, keychains, coins and pens are best kept elsewhere.
- Clean it gently.Velter's nylon and polyester accessories keep their original look longer when cleaned with mild products free of chlorine and abrasives. Spot-cleaning with a damp cloth and then letting it dry is usually all it takes.
Test your sleeve yourself
We recommend checking your sleeve from time to time with the Shielding Tester app. The test takes less than a minute and shows whether the sleeve is blocking the signal. A good routine is to run it every couple of months, as well as after any mishap, such as dropping the sleeve in a puddle or using it in extreme conditions.
What Not to Do with Your Sleeve
- Don't machine-wash it. The drum knocks the fabric against the walls, and detergent with bleach attacks the metallized fibers. Machine washing also voids the warranty.
The fabric used in Velter sleeves keeps its shielding properties even after washing. In a lab test, it was washed at 40 °C (104 °F), and its shielding effectiveness was measured afterwards. Before washing, it ranged from 77 to 84 dB. After washing, the lowest reading was 61.6 dB at 7 GHz, which is still enough to block every wireless interface.
Keep in mind that this was a lab experiment, not care instructions. Sleeves must not be washed, as washing voids the warranty.
- Don't iron it. An iron heats the metallized layer and warps it, and even the synthetics setting is risky. Heat spreads unevenly, and a local hot spot can burn right through the coating.
- Don't submerge it in water. Polyester can handle splashes and light rain, but it doesn't tolerate full immersion well. Water seeps through the seams and gets trapped inside, where the inner layer dries slowly, and the metallized threads in the closed pocket start to corrode.
- Don't keep sharp objects inside. A key or a money clip wears away the inner surface at one specific spot. From the outside, the sleeve still looks intact, but the shielding at that spot is already compromised. Damage like this is invisible to the naked eye, and only a thorough check will reveal it.
Velter fabric has passed abrasion resistance testing.
An independent laboratory put the material through 2,000 Martindale abrasion cycles under ISO 12947-2, the international standard for fabric abrasion testing, and measured its shielding performance before and after. The results did not change. At 13 GHz, the signal measures about 14 µW/cm² without the fabric and drops to roughly 0.4 µW/cm² with it, which is the instrument's noise floor. The same readings were recorded both before abrasion and after 2,000 cycles. Despite the fabric's high abrasion resistance, we still recommend protecting the sleeve from heavy mechanical stress so that it serves you for as long as possible.
- Don't put a wet or dirty phone inside. A phone fresh from the rain or a workout brings moisture in with it, and sand and dust act like sandpaper every time you open the sleeve.
- Don't clean it with harsh chemicals. Solvents, acetone and chlorine-based cleaners damage both the outer fabric and the inner layer. Heavy-duty stain removers fall into the same category.
Simple Care, Lasting Protection
A shielding sleeve never becomes obsolete and never needs charging, but its lifespan depends directly on how it's treated. Caring for it comes down to a few simple habits, and they pay off in years of use without a replacement. Follow these guidelines, and your sleeve will last a long time, with protection that works the moment you really need it.