Curses, I've been caught! I indeed posted my initial query without actually looking at the container (which was all the way at the other end of the house, etc., etc.), not realizing, of course, that an alert FTer would sooner or later notice that the approximations I'd used were in error.

However, 3.5 oz. is not "more than 100 ml," as sailman suggests. That's the whole point, isn't it? 3.5 oz. of something could fill a container significantly larger or smaller than 100 ml - depending on what the stuff is!

In this case, the stuff is toothpaste. The weight is 3.3 oz, and the volume is only 75 ml. If the weight were 3.5 (or 3.6 or 3.7 . . ), the volume would still be significantly less than 100 ml.

By the way, thank you to everyone who suggested just removing the labels and making life easier.

Although, if I didn't actually want to go somewhere, I'd be seriously tempted to take a high school science book to the checkpoint with me.