He was born in Valenza and began his activity as a goldsmith in 1959, depositing the trademark 904 AL and producing serialized models. In the mid-sixties he faced artistic experimentation also in the field of sculpture using materials such as river stones, shells, casting slag, wood, plastic. In 1968 with the artwork "Vigilanza dei diritti umani" ("Human rights vigilance") and with the flint and gold line "Gli antenati" ("The ancestors") he mediated between the most daring instances of contemporary goldsmithing and their wider dissemination, allowing them to spread even the most innovative goldsmithing. This ductile ability would allow him to transpose into precious materials the ideas of other artists such as Melotti, Scanavino, Consagra, Ceroli, Staccioli, Mastroianni. The core of Spalla's poetics is his relationship with nature, in particular with the river Po. The river stone, the pebble, worked by the currents, is the material that fascinates him the most. Spalla creates unique works destined to collectors and small edition lines, produced and distributed by Ferraris & C. He took part in the "Diamanti Oggi" (''Diamonds Today'') competition at De Beers, obtaining two prizes (1972 and 1985) and several mentions. At "Gioiello Inedito" ("Unique Jewel"), he presents Mobilità (''Mobility'', 1979), Riflusso (''Reflux'', 1980), Monte di Venere (''Mount of Venus'', 1983). He was invited to a number of exhibitions: "Tendenzen" ("Tendencies", Schmuckmuseum/Pforzeim, 1973) where his double brooch remains permanently; "Aurea" ( Biennial of Goldsmithery Art, Florence 1974) where he exhibited Sasso e Oro ('Stone and Gold'); "Bestiarium", a travelling exhibition (Germany). In 1989 he was in Japan with "Ten centuries of jewellery art in Italy". In 1993 he was in Florence, at Fortezza da Basso, in the " Author's Precious" section, exhibiting next to Manzù, Afro, Capogrossi, Consagra. Since 1994 he has been in the collections of the MOC, at the Sartirana Castle. In 1995 he was invited to "Torino design: dal cucchiaio all'automobile" (" From spoon to car"); in 1996 he participated in "Aus Italien für die Welt. 100 Jahre Schmuck aus Valenza" ("From Italy for the world. 100 years of jewellery from Valenza", Leipzig) and in 1999 at the "Jewellery Awards" in Beirut. In 2018 the anthological exhibition "Paolo Spalla. Jewellery and Sculptures (1935/2010)" was organised in Palazzo Valentino, Valenza.
L. Lenti, Paolo Spalla, in “L’arte del gioiello e il gioiello d’artista dal ‘900 ad oggi”, catalogo della mostra, 2001, Firenze, Giunti, pp. 375-376.