His technique relied on precision and clarity of line. Many engravers of the period sought to simplify original paintings for easier reproduction. Holloway instead attempted to capture the exact tonal values and textures of the source material. His engravings of Elymas, the Sorcerer, Struck with Blindness and the Miraculous Draught of Fishes demonstrate this focus on detail. He used a combination of etching and engraving to achieve a range of grey tones. This method allowed him to reproduce the dramatic lighting of the figures.

Modern collectors select Holloway for his technical skill and his ability to translate Renaissance designs into a monochrome medium. His engravings offer a structured aesthetic that fits well in contemporary interiors. These prints provide a way to display religious and historical subjects without the heavy colour palettes of original oils. His portraits, such as those of Antonius Triest or Charles Augustus, Duke of Saxe-Weimar-Eisenach, show a similar dedication to likeness.