Prunty's signature work became the Flats and the Cuyahoga River of Cleveland, incorporating both nature and the industrial city. With loose and painterly brushstrokes, he described his work as "Casual Realism." Prunty worked exclusively in transparent watercolor, which allows light to pass through the pigment and reflect off of the white paper beneath it. He used this to his advantage, portraying hazy, atmospheric effects in the city settings of Cleveland. This, combined with his loose brushwork, emphasize the emotional aspect of the scene. The magical qualities of light and atmospheric effects are readily apparent in "Ore Boat on the Cuyahoga." Prunty would start each work with the largest shapes that form the composition and mix his colors on wet paper, allowing them to flow together. He worked from light to dark, saving the white of the paper for the focal point. His middle tones dominate the painting (the boat), and his darkest colors (to the left of the boat) accent the central point of interest.