Everything in the NPM collection is on cotton paper, which ages with time. The protective silk borders and backs are also easily damaged, and a scroll that is frequently rolled and unrolled, or hung on a wall, is susceptible to cracking and creasing.
故宮所藏的繪畫作品皆為絹紙，時日一久，本身也會老化，保護畫幅的裱綾、覆背紙也易破損，畫軸若經常捲收或張掛，也會破裂摺損。