Kate Middleton broke the rule of not wearing tartan past the holiday season ... Kate walked to church on Christmas morning 2017 with a green and red plaid coat over her baby bump.

Plaid Nation Day is right around the corner for the RBC Heritage Presented by Boeing. On Saturday, Harbour Town is set to be covered in a blanket of tartan plaid as far as the eye can see.

Heritage Plaid ... green of Harbour Town Golf Links on Hilton Head Island. But only a small fraction of the jackets seen at the Heritage are made of the authentic, Scottish-imported tartan ...

and a green and blue tartan scarf. She accessorised with fashion-forward footwear in the form of black suede boots, and carried her Grace Han Love Letter Top Handle bag. The Princess styled her ...