What the carry-on rules say, how to pack so the case closes, and how to sleep on a long flight. Every rule links to the official source it comes from.
Carry-on rules
Liquids in a carry-on come down to three numbers. What the TSA's rule says, what counts as a liquid, where the exemptions are, and how to pack so the bag comes out in one move at the checkpoint.
Carry-on rules
Yes, in your carry-on, and never in the checked bag. The limit is in watt-hours, which is not always on the label, and since March 2026 the international rules also cap how many you can carry.
Packing
Plain cubes save order, not space. Compression cubes save some space, mostly with soft clothes. None of them saves weight.
Comfort
Sleep on a plane is rarely good sleep, but it can be better than none. What helps most is timing, the right seat, a head that does not drop, and a plan for getting up.
Security
A lock on a checked bag joins the zip pulls together. It will not stop a security search, and in the US a TSA-recognised lock is the kind an officer may be able to open without cutting it.
Security
They are built to block a signal. Whether that signal was ever the risk is the part worth knowing before you buy one, and the answer is less dramatic than the word skimming suggests.
