Formerly the preferred method for smuggling liquid contraband, flasks have evolved into... well, the preferred method for smuggling liquid contraband.
Fact: in the 18th century, pioneering women smuggled gin onto warships underneath their petticoats in pig bladders. And you thought a normal flask was hard to keep clean
Since its worth toting your own booze around, it's worth doing it right. Here are the qualities you should look for
A Captive Cap: attached is better, because there’s nothing more annoying than losing the top to your favorite flask. Except, you know, tons of things.
Built-in Funnel: the truest sign that you’ve matured is when you use your funnel for alcohol-related precision
Material: flasks made from food-grade stainless steel will spare your top shelf spirits the tin can aftertaste, while plastic flasks allow you to sail through the metal detector en route to early morning court appearances for drinking in public. Glass flasks are ideal for hot liquids... so, stainless steel it is
Form Factor: if you plan to secretly store booze in your hip or breast pocket, flasks with a body-contoured curve are perfect. For hiding hootch in plain sight, everyday items like neckties hide low-profile bladders, and canes with vials in their shafts. For the bolder still, there are flasks disguised as smart phones and walkmen -- perfect if you’d rather look like a refugee from 1998 than a drunk
Size: does count. Most flask capacities fall between 4-8oz, but larger ones (upwards of 60oz) do exist. Incidentally, so does rehab.