Right from the guy who will be applying the grip tape:
I think if they have to question if it is too small, then it is. Tell them to think about having to apply this by hand, which I will be doing. If they don’t think that they could lay their design down, then it should be tweaked until they are comfortable in the likelihood of its application. I don’t want this to stifle creativity and since I am applying the grip, I am will willing to go out on a limb for the sake of design.
A hint for the designers: Using both clear (opaque) and black grip together is the key to the functionality of the design as well as its application. The more negative, unused space, the more likely the grip is to tear away. Filling negative space with clear tape with strengthen the design as a whole.