20 of 26 people found the following review helpful
Sorta spillproof but not really,
This review is from: Trudeau Board Room 16-Ounce Travel Mug, Black (Kitchen)
If you fill this mug with the lid in the closed position and then screw the lid on, it is very nearly leakproof. But once you drink from it, liquid gets trapped between the lower seal and the holes in the lid top. Then, even if in the Closed position, there is a fair bit of liquid to dribble out. Not really, truly ready for prime time but OK if used with caution. I'm on the lookout for something better.