I don't know why it's so hard to find an undershirt that's comfortable, holds its shape, and works well with a dress shirt.  Yet, it is.  I can't be bothered to think about brand loyalty when it comes to something which should be as interchangeable as an undershirt, but my experience with these Calvin Klein shirts may lead me to change my mind.  They wash and dry well without excessive wrinkling.  They stay tucked in, and they're slim enough that they don't disrupt the line of your dress shirt.  I'm very pleased with the purchase.