Even Gilpin's descriptions can seem quite vague, concentrating on how scenery conformed to picturesque principles rather than its specific character.
In one much-quoted passage, Gilpin takes things to an extreme, suggesting that "a mallet judiciously used" might render the insufficiently ruinous gable of Tintern Abbey more picturesque.
Gilpin was born in Cumberland, the son of Captain John Bernard Gilpin, a soldier and amateur artist.
From an early age he was an enthusiastic sketcher and collector of prints, but while his brother Sawrey Gilpin became a professional painter, William opted for a career in the church, graduating from Queen's College, Oxford in 1748.
Both texture and composition were important in a "correctly picturesque" scene.
The texture should be "rough", "intricate", "varied" or "broken", without obvious straight lines.
Although Gilpin sometimes commented on designed landscapes, for him the picturesque remained essentially a set of rules for depicting nature.
It was left to others, most notably Richard Payne Knight, Uvedale Price and Thomas Johnes, to develop Gilpin's ideas into more comprehensive theories of the picturesque and apply these more generally to landscape design and architecture.
He was survived by his wife, Margaret (1725 – 14 July 1807), to whom he was married for over 50 years.
In 1768 Gilpin published his popular Essay on Prints where he defined the picturesque as '"that kind of beauty which is agreeable in a picture" and began to expound his "principles of picturesque beauty", based largely on his knowledge of landscape painting.