Glossary: Gold Leaf Grades — Ku Jin & Chi Jin
术语：金箔成色与库金、赤金
标签：金箔规格, 库金, 赤金, 仿金箔, 选材原则
传统金箔按成色分"库金"（约 98% Au，色偏红黄、耐候稳定）与"赤金"（约 74–92% Au，色浅亮、久置易泛红发暗），现代规格多见 23.5K/24K，标准张 9.33 cm × 9.33 cm、厚约 0.12 μm；仿金箔为铜锌合金，价低但 6–12 个月内氧化发暗，只宜室内短期陈设。选箔原则：户外与触摸件用高纯库金并罩封护，大面积棚顶可用 22K 降本，文物修复须 XRF 核对后与原件成色一致。
Traditional leaf grades split into ku jin (~98% Au, reddish-yellow and weather-stable) and chi jin (~74–92% Au, lighter and prone to dulling), with modern 23.5K/24K sheets standard at 9.33 cm × 9.33 cm and ~0.12 μm thick; imitation copper-zinc leaf is cheap but oxidizes within 6–12 months, fit only for short-term interiors. Selection rules: high-purity leaf plus topcoat outdoors and on touch surfaces, 22K to cut cost on large ceilings, and XRF-matched grade for restoration.