The term 'strong brown paper' can be summarized as a type of Kraft paper, which is a strong and durable paper made from wood pulp. It is often used for packaging and wrapping items, as it is resistant to tearing and water damage. It is also used for craft projects, such as scrapbooking and card making. Kraft paper is available in a variety of colors, including brown, and is often used for its strength and durability.