Classification Table for Washi for Conservation
| Grade | Classification/Level | Fibre Content | Production Method | Example of Papers |
|---|---|---|---|---|
| 1 | Museum/Cultural Heritage | 100% domestic Japanese bast fibres prepared by the traditional method | Handmade. Weak or mild alkalis. No bleach or natural bleach. Undyed. Natural neri. Wooden drying boards. | All UNESCO papers, Seichosen, Seikosen, K-33 (Kurotani), Echizen Kizuki Hosho, Udagami, Misugami |
| 2A | Conservation (I) | 100% domestic Japanese bast fibres prepared by methods as close as possible to the traditional method | Handmade or machine-made. Mild alkalis. No bleach or natural bleach. Undyed or dyed with natural/direct synthetic dyes. Natural or synthetic neri. Heated stainless steel wall or brass | KR4, KR4C, KR5 & all other KR series, Kizuki Tosa Kozo, Kurotani Papers, K-35, Yukyushi, Takogami, Usumino B5/B6, Oguni Papers, Shibori |
| 2B | Conservation (II) | 100% domestic Japanese or Chinese bast fibres or a mixture of Japanese and Chinese bast fibres | Handmade or machine-made. Mild alkalis. No Bleach or natural bleach. Undyed or dyed with direct synthetic dyes. Natural or synthetic neri. Heated stainless steel wall. | Kizuki Somegami “NU” “VA”, Mr. Ebuchi Paper (for ACNT) |
| 3A | Conservation (III) | 100% domestic Japanese or Chinese bast fibres or a mixture of Japanese and Chinese bast fibres | Handmade or machine-made. Strong alkalis. Chemical bleach. Undyed or dyed with direct synthetic dyes. Natural or synthetic neri. Heated stainless steel wall. | Sekishu Roll, Misu Rolls, Kizuki Somegami, Hadaura |
| 3B | Conservation (IV) | 100% imported (normally Thailand-based) bast fibres or a mixture of Japanese and imported bast fibres | Handmade or machine-made. Strong alkalis. No bleach or Chemical bleach. Undyed or dyed with direct synthetic dyes. Natural or synthetic neri. Heated stainless steel wall or coated drying board | Kizuki Kozo Roll 6g, Kinugawa, Okawara Small |
| 4 | Conservation (V) | 100% non-wood plant (leaf vein fibre, such as abaca) or a mixture of such plant fibres, bast fibres or chemically purified wood pulp (the portion of woodpulp is below 30%) | Handmade or machine-made. Strong alkalis. Chemical bleach. Undyed or dyed with synthetic dyes. Natural or synthetic neri. Heated stainless wall or coated drying board | Tengujo Kashmir, Kuranai, Maruishi, Gifu, Kaji Natural, Sekishu Student, Moriki Kozo, Kawanaka |
| 5 | Standard [not recommended for conservation] |
A mixture of bast fibres and plant fibres, unpurified wood pulp or other synthetic materials (the portion of wood pulp is 30% or more) | Handmade or machine-made. Strong alkalis. Chemical bleach. Undyed or dyed with synthetic dyes. Natural or synthetic neri. Heated stainless steel or iron wall. | Shiohara, Yatsuo Series, Kozo Natural, Mulberry |