Most book illustrations of the time were in black and white drawings for books for adults or young adults. Colour was only used for books for small children or for the frontispieces of other books. Houfe states that he specialised in children's stories, especially those with figures in costume. Petherick worked on several full colour books, including London Characters (1875) by Laura Valentine which showed 36 different occupations in London. Twenty-nine of the 11 x 7 cm vignettes on which the book was based were sold for £1,200 in 2007.
