Paper or paperboard coated with a foam coating layer comprising nanocellulose

A coated paper or paperboard comprising:

• a paper or paperboard substrate, and
• a solid closed cell foam coating layer disposed on a surface of said paper or paperboard substrate,
• wherein said solid closed cell foam coating layer comprises:
• 60-99.5 wt % of a nanocellulose based on a total dry weight of the closed cell foam,
• 0.1-10 wt % of a polymeric foaming agent based on the total dry weight of the closed cell foam,
• 0.1-20 wt % of a polymeric dispersing agent, or a polymeric rheology modifying agent, or both based on the total dry weight of the closed cell foam,
• wherein the solid closed cell foam comprises closed cells trapped inside a matrix formed of the nanocellulose, the polymeric foaming agent, the polymeric dispersing agent, the polymeric rheology modifying agent, and optional other additives.