This is the 12390th most frequent Russian word.
картонная
Made of cardboard.
"Картонная" here describes the type of paper used.
Он вырезал фигуру из картонной бумаги.
He cut out a figure from cardboard paper.
Here, "картонная" (cardboard) acts as an adjective describing the material of the box.
Моя младшая сестра построила дом из картонной коробки.
My younger sister built a house out of a cardboard box.
In this sentence, "картонная" specifies the material of the sculpture.