What is the purpose of the warning that say “Do Not Shake” on dry erase markers and Sharpies? Does something bad happen if you do? Why don’t they warn against sniffing them?
Because if you shake them you can actually force ink out of the writing tip. If the cap is off you will splatter ink around the room. If the cap it on it will drip and create a mess when you next open it.
And NEVER, EVER unscrew the cap on a technical pen (Rapiograph) on an airplane. India ink can squirt out of the tiny tube in a stream up to 20 feet.