Along with his brother, Filippo Collino (ca 1737–1800), Ignazio worked in a restrained formal style, intermediate between Baroque and Neoclassicism.
He went to apprentice with the bronze sculptor François Ladotte (Francois Ladatte) and in drawing with Claudio Francesco Beaumont in 1744.
In Rome, he copied many antique originals, including busts of the Emperor Marcus Aurelius, of Faustina, and of a Vestal.
He provided much sculpture for royal tombs of the House of Savoy at the Basilica of Superga, including the Monument for Carlo Emanuele III (1773).
He also helped complete the royal tombs for the king of Sardinia, in the church of Superga, and finally the colossal statue of St. Agabus in Novara.