Often123:
Which are those, Lonewulf?
The "amateur" artist website is AnimeOTK which focuses on fanart, yet some artists there are quite polished. For instance David Ell, who regularly produces shorts about his titular character Sammy Simpkins. but he isn't (as far as I know) published in mainstream media.
The "professional" artist website is simply differentiated by those who have produced mainstream comic books which incorporated spankings in years gone by. That one is ChicagoSpankingReview (dot org)