Particular specification:
* Fe 3 content (%): ≥ 95
* Reduction (contrast with standard): da -0. 5~0. 5; dB -0. 5~0. 5
* Tinting strength(contrast with standard): 98-105
* Volatiles under 105:   ≤ 1. 0
* Water soluble matter(%): ≤ 0. 5
* PH of aqueous eztract solution: 5~8
* Oil absorption (g/100g): 15~25
* Residue on sieve 45un(%): ≤ 0. 10
* Productivity: 6500 T/year