2.1.2. Preparation of lac dye
Stick lac (500.90 g) from the Rain tree, Samanea saman
(Jacq.) Merr. (Pithecolobium saman, Mimosaceae), in northeast
Thailand (Nakhon Ratchasima) was finely powdered (18
mesh) in a grinding mill. The powdered material was
extracted with deionized water (1.5 L) at 60 C for 1 h. The
aqueous solution was filtered, the filtrate concentrated under
reduced pressure (rotary evaporator) and then freeze dried to
give a crude lac dye extract (36.07 g), which was then used
without further purification.