Commonly known as SOGA 91, when coupled with Diazo Salts produces a variety of rich chocolate browns which can be discharged (bleached back) to either white and/or series of shades of brown.

It enables the batik craftsman to work ( for a few stages of their batik work) in a positive rather than in negative form. The main advantage is that dark toned tjanting lines and dots are easily achieved.

The process involves dyeing the material with SOGA 91 and a Diazo solution before any wax has been applied to the cloth. The dyeing is done in a two bath method - same as in Naphtol dyeing.

DYEING

First dye bath: 5g SOGA 91 to 1 litre of water

Soga is dissolved in a small amount of hot water and than made up to a litre with more hot water. If it happens to "gum up" during pasting just add a bit of Methylated spirits. Wet the cloth and immerse in Soga bath for 5 minutes. Lift material out and allow to dry.

Second dye bath; 10g Diazo Salt to 1 litre of water (see note ***)
Immerse cloth for 5 minutes. Rinse thoroughly. If the colour is not dark enough, the whole process must be repeated.

DISCHARGING-BLEACHING

First bleach bath:	5g Potassium Permanganate (condies crystals)
	3 ml Hydrochloric Acid 30% or 10 ml Muriatic Acid (from hardware shops)

Dissolve Potassium Permanganate crystals in 1 litter of water and carefully add Hydrochloric acid. Wet the cloth and immerse in the solution. The longer the cloth is left in the bath, the more pronounced is the "bleach" effect. Lift out and hang it for few minutes.

Second bleach bath

15g Sodium Hydrosulphite

Dissolve in 1 littre of cold water. Here again, the length of time the material is immersed will determine the amount of bleaching If bleaching is not white enough, repeat the 2 bath again.

NB To achieve delicate and gradual successive stages of lighter tones of brown, the strength of two baths should be slightly weakened especially for the first bath. Cloth test should always be done beforehand to ensure desired amount bleaching.

*** A variety of Diazo Salts can be used to obtain shades of colour from pale reddish brown to very dark chocolate brown.

SOGA 91 5g/litre	Diazo Yellow GC 10g/litre	.
	Diazo Orange GC 10g/litre	.
	Diazo Scarlet R 10g/litre	.
	Diazo Red 3GL 10g/litre	.
	Diazo Red B 10g/litre	.
	Diazo Bordeaux GP 10g/litre	.

Using proportions 2 : 5 produces only slightly paler strength of shade of above colours.

SOGA 91	$33.95 100g
Potassium permanganate	$10.95 50g

Soga 91 is the dye used in production of traditional Indonesian batiks from Yogyakarta and Surakarta region
of central Java. The colours are equivalents to those made with natural dyes used in the last century.