Description of the flag
From Barraclough (1971):
"Sikkim, formerly a protectorate of India, was incorporated as the twenty-second state of the union in May 1975, and the office of the hereditary ruler, the Chogyal, was abolished. Sikkim has, or had, a flag of white with a red border all round, and a yellow Chakra (fimbriated in red) in the centre."Don Hagemann, 28 November 1995
"...the Chakra [is] a Buddhist symbol representing the Law of Dharma, or eternal change." The Chakra on the flag of Sikkim is different then the one on India's flag. It has eight spokes rather than the many spokes on India's, and has an ornate "nub" on the wheel at the head of each spoke.
[editor's note: The source of this quote is not Barraclough (1971), but probably a later edition of the Carr-Barraclough-Crampton series]
In Flags of Aspirant Peoples the flag of Sikkim is similar to the one above with minor differences in the Chakra.
Ivan Sache, 16 Sep 1999
Sikkim was an antiquated Shangri-La anachronism with a fairly ineffectual Chogyal (Gyalsay Palden Thondup Namgyal) whose only claim to fame was marrying New York socialite Hope Cook. India was never comfortable with this weak link in its China defences. All the same, India's annexation of Sikkim (during the controversial emergency rule of Indira Gandhi) was widely regarded as unnecessarily heavy-handed. India pretty much forced a new constitution on Sikkim, which considerably reduced the Chogyal's powers (he had ruled as a feudal autocrat). There was also a referendum in Sikkim in favour of union with India, (although there is some uncertainty how free the poll was). This was ratified by the 38th amendment to the Indian Constitution (making Sikkim its 22nd state) on 26 April 1975. Unlike the Tibet issue which never dies, I don't think anybody seriously thinks of Sikkim independence.
Todd Mills, 23 September 1997
1877 - c. 1914
Country: Kingdom of Sikkim
Use: national flag, CS*/*** 
Source: Flag Institute archive, M. Lupant archive.
Accuracy: reproduced from a drawing of L. Philippe in the M. Lupant collection.
To reduce the file size I had to simplify a little the colors in this file.
c. 1914 - 1962
Country: Kingdom of Sikkim
Use: national flag, CS*/*** 
Proportions: ca. 7:9
Source: "Kosmos Sammelbilder" Memmingen, Germany, 1951
Accuracy: reproduced from a drawing made out from a color photograph of the flag.
Carr (1961) says:
The State of Sikkim has an ornate flag of unusual design. It comprises a white field, three edges of which have a triple border, red, white, and blue, the latter being the inner one. An ornamental circular emblem in red is superimposed in the center of the field, and the remaining area has a variety of minor charges in red, blue, green, and yellow. These colors are also used for the decorations on the aforesaid red portion of the triple border.Jarig Bakker, 14 August 2000
1914 Design: Blue border with orange and red brick-a-brack narrower borders thereon, with thinner white and red borders towards the inside; inside the panel shows red wheel having shadings (in between the spokes) of red/blue/yellow/blue, while the 2nd (left central) motif had *2* round frame rings. The 6 motifs colored as gold frames, with red/yellow/blue charges.
Robert Wheelock, 20 October 2005
1962 - 1967image by Mario Fabretto modified by Robert Wheelock, 19 October 2005
Pictured in b&w in Barraclough's 1965 edition of his book Flags Of The World, the old 1962-1967 flag design that did belong to Sikkim was an elaborate one. Here's a description of the looks of the 6 'foetal' charges (which look like amoebas or tadpoles of some sort) that are around the Buddhist prayer wheel inside the flag:
- 1. Top left: Tadpole-like, having its face (eyes & mouth) pointing towards top, with 2 tails
- 2. Central left: Somewhat like an earthworm, with small diamond-like head & palette-like stomach; left tail protrudes from tummy, while right tail goes from the right side of its head
- 3. Bottom left: A young serpent-like (looking like an archer's bow) ameba, with flaps protruding from its 2 arms, a main (bottom) tail, & an additional tail that stems from its neck
- 4. Top right: Snake-like, with 4 loops & a tail coming from its chest
- 5. Central right: Toad-like amoeba, with a head loop, 2 knobs (for its arms), & 2 tails, which shoot off from its head & butt
- 6. Bottom right: A sea plant, complete with roots, a trunk, & branches.
The basic setup of that design is diagrammed as follows:
[around the chief, fly, & base edges]
RED OUTER BORDER (with V in-cresc & Y out-cresc+B ticks)
WHITE MEDIAL ORLE
BLUE INNER ORLE
[WHITE INSIDE PANEL]
Y sun with R haze Y sun with R haze
 R Buddhist Khorlo Pray Wheel 
The red border is outlined in maroon, the blue inner orle is outlined in navy blue, & the Khorlo Wheel is red outlined in maroon.
Robert Wheelock, 12 June 2000
E. C. M. Barrclough says in Flags of the World:
The Kingdom Of Sikkim [as it was then] had a flag that flown there from 1962 till 1967; it was in existence for around 5 years. [It was] an ornamental flag of an unusual design. It comprise[d] of a white field, the chief, base, and fly sides of which had the 'triple border' of red (outer)/white/blue (inner). A big red Khorlo prayer wheel is centered thereon, while the remaining panel area was charged with a variety of various religious motifs in shades of red, gold, green, and blue. The thick red portion of the 'triple border' had smaller charges (what looked like crescents and 'ticks') in yellow, green, and blue.contributed by Robert Wheelock, 18 January 2001