After an unfortunate incident involving my passport and some alcohol-based hand gel in my bag, I decided I needed some sort of waterproof passport protection. But searching around for "passport wallets" mostly doesn't result in anything waterproof and all the wallets are large, bulky or ugly. But there is a really simple solution.A 4 mil ziploc bag of the appropriate size. What's the appropriate size? Well, there's an ICAO standard for machine-readable passports which uses the ISO/IEC 7810 ID3 size for the "passport booklet" (what you and I would call a passport).So, that's 125 x 88mm. Happily, a pretty common ziploc bag size is 10 x 15cm (or 100 x 150mm, if you prefer). That gives you an extra 12mm horizontally (so the passport will slip inside) and 25mm vertically (space for the passport and the area with the ziploc closure).I mentioned "4 mil" above. Switching to non-metric measures (which seem common for the thickness of plastic) that's four 1/1000s of an inch (note it's not "millimetres", it's "mils"). You also sometimes see plastic measured in microns (which is 1/1000 of a millimetre). 4 mil bags have a sturdiness to them that thinner plastics do not have. They are sometimes described as "extra thick". In the UK, these folks (not an affiliate link) sell through Amazon and have a variety of bags of the right size and thickness.And now my (new) passport is carefully protected.Aside: it turns out I actually once owned a waterproof passport wallet. I was gifted a SÜLgear passport wallet and lost the waterproof liner. The kind folks at SÜLgear pointed out that the waterproof liner was simply a 4" x 6", 4 mil ziploc bag (or, for those of the metric persuasion, 102 x 152mm).
First seen: 2025-10-06 11:05
Last seen: 2025-10-06 11:05