ainbridge is chiefly remembered for his publication of The Fly Fisher's Guide in 1816. He was a Liverpool banker, who fished the Tweed, and was a neighbour of Sir Walter Scott. Scott wasn't totally enamoured of Bainbridge to begin with, referring to him as "a dog of a banker" in his diary. Despite a further entry where he suggested that he would have had his neighbour "dirked to a certainty," Scott got over it, and the pair seem to have got on reasonably well after a shaky start.
The Guide is remarkable because it was one of the first books on fishing with colour illustrations to reach a wide audience. The book presents forty-four trout flies "copied from nature," with illustrations of the naturals that the artificials were supposed to copy. Bainbridge's trout flies were shortly to be eclipsed by Ronald's lists, but Bainbridge also lists five salmon fly patterns; notable not only because they are among the earliest known dressings of salmon flies, but also because one of them is a "gaudy" fly.
Bainbridge does highlight a radical change in the way trout flies were being tied: he published the first colour plate which showed wings being made from paired quill slips and tied on with the tips facing backwards (towards the bend of the hook.) Prior to 1800, wings on British trout flies were usually formed from a single rolled segment of quill fibres tied on with the points facing forwards (away from the bend of the hook), following which the bunch was then folded back and over-wrapped at the base to keep it secure - the reversed wing style. This resulted in a relatively upright wing, which sat at an angle greater than forty-five degrees to the hook shank and it is shown very well in early woodcuts.
After Bainbridge flies were increasingly tied with a down-wing that was set on with the tips facing backwards and the whole of which lay at an angle of around forty-five degrees to the shank - the classic down wing tie which we are familiar with today.