Every spanking illustration is a spanking artwork, but not every spanking artwork is a spanking illustration. This is because many spanking artworks were created as "standalone works" and not to illustrate a given piece of text.
Spanking illustrations come different categories:
Child spanking illustrations
Many of the oldest spanking illustrations we know of show how pupils and novices were disciplined by their teachers at school. The illustration on the right is such an example. The drawing elucidates how in this Amsterdam institution in 1662, a delinquent was laid on a bench and had his head locked in place by some kind of wooden bar, while receiving a birching on his bared buttocks. (This illustration is also interesting because it shows an early piece of spanking furniture.)
From the mid-19th to the mid-20th century, people began to debate whether children should be spanked at all, or whether corporal punishment was too dishonoring. Publications of that time sometimes featured spanking illustrations, often in the popular form of humorous cartoons.
Norman Rockwell was one of the best-known illustrators who created fine illustrations for the weekly cover page of The Saturday Evening Post, more than one of which show a realistic rendering of a child spanking scene of the time.
Adult flagellation illustrations
Another category of spanking illustrations are those that depict adults being flagellated or flagellating themselves, e.g. as religious penance. There are also many whipping illustrations of judicial corporal punishment, but these whippings are typically applied to the delinquent's back and not buttocks, so these can not be called 'spanking illustrations'.
Erotic spanking illustrations
In the first half of the 20th century, authors published printed spanking fetish stories (spanking novels) that featured spanking illustrations which were drawn by artists such as Louis Malteste. Many of these were published in France — see early 20th century French spanking literature. The spankees in these stories and illustrations inlcude both minors and adults.
In the second half of the century, spanking magazines came up that regularly published illustrated erotic spanking stories, which became employers for spanking illustrators such as Eric Stanton. With some exceptions such as Jay Em and Sassy Bottoms, these magazines would typically avoid featuring minors as spankees and cater largely to the adult/adult spanking market.