PURPOSE: To prepare the title compd. with excellent color tone stability under heat, by dispersing or dissolving a specified monoazo lake pigment in a solvent which contain polyhydric alcohol, and adding a solution of a Ca salt dropwise to it under heating.

CONSTITUTION: Brilliant Carmine 6B monoazo lake pigment of formulaIis dispersed or dissolved in a solvent which contains a polyhydric alcohol (e.g. ethylene glycol), followed by heating to 40W220°C. Then a solution of a Ca salt (e.g. CaCl2) in an identical or different solvent is added dropwise for formation of the title compd. of formula II in plate crystals having red color and pearly luster.

EFFECT: The compd. has improved thermal stability, for it contains no water of crystallization which comes off at 70W80°C but contains high-boiling polyhydric alcohol in the crystal.

USE: Coating, cosmetic, printing ink, etc.