Botanical Name

onosma hispidum

Common name

purging nut

Other Name

physic nut, barbados nut

Part Used

trees bark & wood


textile dyeing, ayurveda-syphilis and leprosy

Color Ranges:

Product Descriptions:

Onosma Hispidum In India name as Ratanjot. It is found in North western Himalayas from Kashmir to Kumaon ( Uttarakhand) at a altitude higher than 2300 m. the roots of this plant are main source of yieldingsilver grey colors. By combination of different mordant like alum, copper sulfate, ferrous sulfate in desired ratio will give it better colorfastness properties.

Dyeing Process

sodhani biotech

(A) Pre Mordant 1 :- Pre-treat the material with alum 10% of fabric weight at 80°C for 60 mins.
(B) Dyeing :- Add the required amount of dye to the dye bath. PH of dye bath needs to be maintained at pH 7. If it's higher than pH 7 add vinegar, if below pH 7, use lime or soda ash. Stir well to dissolve the dye. Add fabric to the dye bath and maintain at 90°C for 60-80 mins. We check all our natural dyes at 30% of fabric weight, you can amend the percentage as per lighter or darker shade required.
(C) Post Treatment :- Conduct soaping of the dyed material with non-ionic detergent (0.5gpl) at 50°C for 35 mins.
(D) Hot wash and then cold wash the material.


Connecting with us is easy and simple. Just subscribe now!