Although Henshall did paint some oils he was principally a watercolourist, being elected an Associate of the RWS in 1883, and becoming one of the Society's forty full members in 1897.
While Henshall did paint some oil paintings, his primary artistic focus was on watercolors. He achieved recognition as an artist by being elected an Associate of the Royal Watercolour Society in 1883 and becoming a full member in 1897.