From The Postage Stamps of J&K Simplified by Dawson & Smythies, pp 5-6.
Kashmir was at one time under the Afghans, when three classes of postal runners were maintained: for state correspondence, for the use of state officials, and by private traders for their own use. When Maharaja Ranjit Singh drove out the Afghans in 1820 he kept on the same system, which remained unchanged until 1847, when Maharaja Gulab Singh reorganised the entire postal arrangements and established a line of mail runners between Jammu City and Srinagar, with mail stations at fifteen other places. All letters were transmitted free of any charge. Nine years later the number of runners was increased, consequent upon the compaint of the traders that their letters took a long time to reach their destinations. In 1858 postal rates were ordered to be levied on all private letters which were, at the same time, required to be sealed in future. This system of seals or ‘franks’ continued until the introduction of postage stamps in 1866.
The seals were apparently six in number, three for Jammu and three for Srinagar. They were octagonal in shape, measuring about 23 mm high by 25 mm wide, and bore lengthy inscriptions in Sanskrit. They were impressed on the outside of the letter in dull purple for Jammu and dull red for Srinagar. Fewer than twenty of these franks are known to have survived.
In 1866 these franks went out of use, but other seals were introduced for cancelling the new adhesive stamps. These were all engraved in Persian, indecipherable, except in the case of the last square Jammu seal. The first of these cancellation seals were circular; Jammu and Srinagar each had one of the same size 19 mm in diameter, impressed originally in magenta and brick-red, respectively. The colour of the former seal was changed to black in 1868, upon the introduction of red as the standard colour of all Jammu stamps. The Srinagar seal continued in use until 1878. [Copyist’s note: There is attestation until August 1879.]
Early in 1870 the second Jammu seal appeared, a square with sides 19 mm long, but with the corners rounded off. It was always impressed in black, and continued in use until the series of special postmarks was introduced in 1878. This seal bears the inscription “Muhr Ahan Kān Jammūn 1915”. This year of the Samvat era corresponds with 1858 and the inscription may be translated “Seal of the Jammu Iron Mines 1915”. It is not known how exactly it was used before it became a postal cancellation, but what makes it specially interesting was that it was struck in red on pieces of paper in September 1877 as a provisional ½a stamp.
At the Leh post office two seals were used, the first was similar in size and appearance to the Srinagar seal, but this was replaced very soon by one much larger, 18 mm in diameter. Both seals were struck in brick-red, but they are very seldom found.
The Srinagar seal, impressed in black, is known used as a frank upon two unstamped letters which passed through the post in 1875.
It may be mentioned here that stamps were pen-cancelled in post offices other than Srinagar, Jammu, and Leh, as they were not supplied with special obliterators. It was not until 1878, with the introduction of the New Rectangulars, that there was any appreciable use of pen-cancllations for fiscal purposes. Hence pen-cancelled stamps of the older issues may all be taken as having been postally used.