Xuan paper used in traditional Chinese painting is commonly available in several standard sizes, such as Three Chi (三尺), Four Chi (四尺), Five Chi (五尺), Six Chi (六尺), Eight Chi (八尺), and Zhang Er (丈二). The "Chi" used in painting and calligraphy measurement differs from the modern unit of length. For example, a full sheet of Four Chi Xuan paper has dimensions of 68 × 136 cm. "Half-sheet" (对开) or "Third-cut" (三裁) refers to splitting the full sheet into two or three equal parts, respectively. Generally, a full Four Chi sheet is approximately eight square Chi, a half-sheet is four square Chi, and one square Chi is roughly equivalent to 33 × 33 cm.
Standard Sizes for Traditional Chinese Painting：
1. Small work: 33 × 33 cm, 1 square Chi
2. Small work: 45 × 33 cm, 1.4 square Chi
3. Four Chi, Third-cut: 68 × 45 cm, 2.8 square Chi
4. Four Chi, Half-sheet square: 68 × 68 cm, 4 square Chi
5. Four Chi, Half-sheet long strip: 34 × 136 cm, 4 square Chi
6. Four Chi, full sheet: 68 × 136 cm, 8 square Chi
7. Five Chi, full sheet: 81 × 155 cm, 11.5 square Chi
8. Six Chi, full sheet: 96 × 178 cm, 15.6 square Chi
9. Eight Chi, full sheet: 122 × 244 cm, 27 square Chi
10. Zhang Er, full sheet: 144 × 366 cm, 48 square Chi
11. Zhang Liu, full sheet: 200 × 498 cm, 92 square Chi
Mounting Format Terminology：
1. Unmounted Xuan paper: Soft sheet (软片)
2. Backed with one layer of Xuan paper: Mirror center (镜心)
3. Backed with one layer and bordered: Mirror mount (镜片) (Framed as 镜框)
4. Mounted with top rod and bottom axle: Hanging scroll (立轴)
5. Horizontal mounting: Horizontal scroll (横披)
6. Narrow, long horizontal scroll: Handscroll (手卷)
7. Bound in album form: Album leaves (册页) (Measured in "K" - 开)
8. Fan-shaped mounting: Fan leaf (扇片)
9. With fan ribs: Folding fan (成扇)
10. Round fan surface: Round fan (团扇) (Large round fan also called 圆光)
11. Written on letter paper: Letter (信札) (Measured in "Tong" - 通)
Formulas for Calculating Xuan Paper Area：
1. Length (m) × Width (m) × 9 = Square Chi
(Example: Four Chi full sheet 1.36 × 0.68 m × 9 = 8.32 square Chi. Basis: 1 m² = 9 square Chi, calculated in meters.)
2. Length (m) × Width (m) / 0.1089 = Square Chi
(Example: Four Chi full sheet 1.36 × 0.68 m / 0.1089 = 8.4 square Chi. Basis: 33 × 33 cm = 1089 cm², calculated in centimeters.)