Born in Glasgow, William Guthrie (1851 - 1939) and his brother John (born Edinburgh 1847) were the sons of painter and decorator John Guthrie of Auchterarder, Perthshire. When John Senior retired in 1870s, he left an already established Stained Glass firm to his sons, who both attended Glasgow School of Art during the 1870s. From 1884 the brothers expanded into stained glass design and manufacture, and the painter James Guthrie (no relation), a leading 'Glasgow Boy', was one of the notable artists they briefly employed, for Knockderry Castle in 1887. William Guthrie was also a landscape painter in oils and watercolour, specialising in Highland scenery.

References:

The Dictionary of Scottish Art and Architecture by Peter JM McEwan