Why did Thomas Gainsborough probably not paint his earliest landscapes directly from nature?

Thomas Gainsborough likely did not paint his earliest landscapes directly from nature because, during that period, he was heavily influenced by the styles and compositions of 17th-century Dutch landscapists, such as Jan Wynants and Jacob van Ruisdael.1

Rather than working en plein air, Gainsborough’s approach to landscape painting was rooted in these artistic influences and the conventions of the time, where "fancy held sway". Even in works like Cornard Wood (1748), which contain significant naturalistic detail, he relied on these established artistic models rather than direct observation of the outdoors. Later in his career, particularly during his time in Bath, he further moved away from direct nature study, often working from memory and creating "little model landscapes" in his studio to use as references while drawing by candlelight.12