Lovers of Indian curries will be familiar with turmeric. It's that spice that gives the strong yellow colour to curry. And if you've ever played around with it, you'll know how it tends to penetrate everywhere, and stay.
Not easy to wash it off.
Fine stuff ... in curry; not really such a good idea when used in the ink to print postage stamps, though. Jammu & Kashmir thought it was worth a try anyway, in 1884, when they were casting about for a yellow ink for their new 1/8 Anna stamp.
The first attempts weren't terribly promising

Watering the mixture down produced rather mixed results

But even at its best, the results were never really terribly satisfactory:

And heaven help the misguided collector who tried to soak these stamps:

Eventually, the Kashmiri authorities gave up on the organic thing, and turned to the new-fangled chemical inks:

Rather a pity, really. I liked the earlier ones better

The 1/8 Anna stamp (equivalent to about an eighth of a cent) was introduced as a special concessional rate for European visitors to the State sending postcards; the normal rate was ¼ Anna. There was a catch though. The Jammu & Kashmir stamp would only carry the postcard as far as the border with British India: to go any further, the visitor had to attach the stamp to a British Indian ¼ Anna postcard.
Despite the concession (and even better value, actually, because the Kashmiri Anna was worth only about half an Indian Anna), these stamps are quite hard to find properly used on postcards.