Table of Contents (below)
     Dual Franked Covers (India)
     Dual Franked Covers (China)
     Single Franked Covers (Bhutan fiscals to domestic addresses)
     Single Frankfurt Covers (Bhutan fiscals to India and other international destinations)
     Philatelically inspired covers (unaddressed covers, favor cancels)

Other Pages in Postal History menu at left:
     Surcharged fiscals on cover
     Robinson numbered covers
     "Modern" use of fiscals (in period during which runner system existed after establishment of civil mail system (Bhutan P&T) (1962 - ca 1988)
     Fakes
     
    

Piece of larger cover

This is a single-franked cover - the Indian postal stationery was used only for convenience, not to prepay Indian onward postage.

To Nepal

To Bombay, southern India (beyond the Sikkim-Kalimpong local area where runners would operate.

Not in Robinson List

This cover was favor cancelled, and the person who requested the cancel stamped his address on the cover after receipt.  It never passed through the mail. 

Army canx w western date schema

Army canx w western date schema

May possibly be tax "cancellations", not postal.