He was born in the city of Amritsar in 1883. His father, Taba Singh, a comb-maker by profession, supplemented his meagre income by dispensing ayurvedic medicines in his spare time. At the age of five, Gian Singh was sent to school run by Giani Thakur Singh, who later rose into prominence as a Sikh missionary and scholar. Giani Thakur Singh's influence on him was everlasting.

After he had passed his primary school, Gian Singh was apprenticed to Nihal Singh Naqqash, a third generation descendant of Bhai Kehar Singh Naqqash, who enjoyed court patronage under Maharaja Ranjit Singh. Gian Singh served his apprenticeship for 14 long years until the death of his mentor in 1905. He brought to his passion for drawing unusual powers of observation and concentration. He made rapid progress in his art and soon began to collaborate with Jawahar Singh Naqqash, a brother of his erstwhile teacher, in working on ornamental designs in the Golden Temple.

Gian Singh's fame will rest principally on his fresco-painting on the walls of the Golden Temple. The art of fresco-painting consists in transferring the outline (khaka) of a design on wet plaster and then filling the outline with appropriate colours before the plaster dries up. The basic colours thus established are worked with requisite details and light and shade achieved with dots and streaks. The colours used are indigenously prepared: red ochre from hirmachi, yellow ochre from gulzard, emerald green from sang e-sabz, lamp black from burnt coconut, ultra marine from lajvard and white from burnt marble.

While much of Gian Singh's work on the outer walls of the domed structure, on the topmost storey, stands partially erased by wind and rain, that on its inner walls yet survives in its original freshness. One dehin executed by him in the sanctum on the first floor, just above Har ki Pauri, bears testimony to his inimitable workmanship. Dehin, the most fascinating item of fresco-painting was Gian Singh's forte. It is an imaginative ensemble of forms taken by the artist from animal or vegetable life, so curiously intertwined as to present a composite and organized whole.

Structurally, dehin has three parts - a pedestal, a vase poised on the pedestal and a bouquet of flowers or a floral bush called jhar. On the pedestal are depicted birds or animals in various dramatic postures - in erotic clasp, in combat or one chasing the other. These figures are often intertwined with creepers.

The other items of note in fresco-painting are floral "square" (murraba) and "rectangle" (tilli). These are used in wall, floor or ceiling decoration. The square usually consists of a fine setting of flowers, leaves, creepers or bushes within a flowery border with handsomely patterned corners. A typical example of a square done by Gian Singh is the one called Acquatic Harmony. It takes for its motif a number of fish encircling a tortoise, with others frolicking around the first set in a circular rhythm.

Gian Singh introduced a number of innovations in the art of fresco-painting. His predecessors in the Sikh school of art depicted gods and goddesses in the body of the pedestal in the manner of their Persian or Mughal forerunners. But Gian Singh replaced these motifs with those of "grapples" (pakran) of animals, birds, flowers, creepers, etc. He also painted historical Sikh shrines on the body of the vase formerly left blank. In addition to this, he brought shade work to a high standard of perfection and gave a poetic touch to his compositions by making them rhythmically balanced and elegant. The colours he used were always bright and attractive.

Apart from fresco-painting Gian Singh tried his hand at several allied arts such as (gach) stucco work, (jaratkari) mosaic work and (tykri) cut-glass work. He was an expert in gach work which consists in carving embossed designs on partially wet layers of plaster of Paris and afterwards, when completely dry, covering it with gold leaves with an undercoat of varnish. Verses from the Japu(F) have been rendered in this style under the arches leading to, the sanctum in the Golden Temple. Another type of work popularly known as tukri work, much in vogue in Mughal days, consists in setting pieces of glass, gold leaves or precious stones in gach work in artistic patterns. The tukri work on the inside of the dome in the central sanctum of the Golden Temple executed in its entirety by Gian Singh, bears witness to his sense of design and his patience and assiduity.

Gian Singh not only prepared designs for Jaratkari (mosaic) work in marble to be executed by craftsmen from Delhi and Rajasthan, but also selected stones of appropriate colour and grain to be laid in the marble. The mosaic designs were based on colourful representations of flora and fauna or on themes picked from Hindu mythology.
Gian Singh was a master of free-hand drawing. His pencil kept pace with the abundance of designs and ideas which flowed from his fertile mind as some of his published works like Nikashi Darpan, Vishkarma Darpan, Nikashi Art Sikhya and Taj-e-Zargari, indicate.

In the Nikashi Darpan (1924), he has drawn stylized forms of various flowers side by side with their natural forms, showing how the latter could be improved upon for the purpose of adjustment in a design. It also contains line work studies of birds and animals, different limbs and organs of the human body, border designs in rectangular, square, half patterns, allover patterns and vase stands composed of rhythmically intertwined animal, bird and plant forms. The Vishkarma Darpan (1926) is a profusely illustrated manual of decorative, architectural and furniture designs. The Taj-e-Zargari (Vol. I, 1920, and Vol II, 1930) contains 1539 designs of Indian ornaments. The Nikashi Art Sikhya (1942) contains scores of sketches designed to initiate a beginner into the intricacies of drawing.

While toiling at larger works, Gian Singh found time for painting easel pictures in which he could freely indulge his humour. Some of his canvases are notable for their originality of conception and workmanship. His painting Types of Irreligion, which illustrates a well-known couplet of Kabir, is a biting satire on charlatans who dupe the naive and the gullible in the name of religion. The Eternal Strife, based on a mythological theme, represents the forces of Good (suras) locked in mortal combat with those of Evil (asuras). The Elephant Fight allegorizes Maya and its victims. It depicts two male elephants (victims) contending fiercely for the prize - Maya in the form of a female elephant who, standing at a distance, contemplates the fight with sadistic mirth.

In appreciation of Gian Singh's exquisite work in the Golden Temple, he was presented, in 1949, with a robe of honour by the Shiromani Gurdwara Parbandhak Committee. During his apprenticeship, Gian Singh had prepared a set of paintings on the Ten Sikh Gurus which was printed in Germany. It became very popular.

Gian Singh died in 1953. Another famous Amritsar artist, G.S.Sohan Singh, was his son. His eldest son, Sundar Singh, was killed in the Jallianvala Bagh firing.

Source: Encyclopaedia of Sikhism, Harbans Singh