The son of a silk merchant from Lyon, Gignous displayed a precocious talent for painting and enrolled at the Brera Academy of Fine Arts in 1864, attending the courses on landscape taught by Luigi Riccardi and then Gaetano Fasanotti.
He came into contact with the Milanese Scapigliatura movement when still very young and formed a close friendship with Tranquillo Cremona.
He began to focus exclusively on landscape in the 1870s, experimenting with painting en plein air and producing views of the Lombard and Piedmontese countryside that he showed at all the major national exhibitions.
Some biographical notes written by the artist’s wife Matilde would appear to bear out the hypothesis of a trip to Paris in the company of Carcano in 1878 and attest to friendship with Vincenzo Vela, who was apparently his host on numerous occasions in Ligornetto.
A recognised leader of the Lombard school of painting, he lived in Stresa (Verbania) and on the coast of Liguria from 1887 to 1906, with long stays in Venice.