I bought (4) 20oz personalized cups & EVERYONE AGREES that the lid needs a design tweak that seems so minimal we can't believe your team hasn't thought of it yourselves!
Please -- on behalf of all others with the same issue -- add tiny "friction spots" or grooves on the lid so that its not too smooth to be unscrewed!
A few times I've had to leave home without my cup because I couldn't unscrew the lid to wash it -- which defeats the point of having it! One of our 4 lids is now cracked becaus