Wrightson uses his styling he utilized on the illustrations for Frankenstein by Mary Shelley project from three decades ago. This style approximates old woodcut-style engravings seen in 18th century books. This is something that Franklin Booth also did in his own inking style.
More Bernie Wrightson.
House of Mystery #231, May 1975, Wrightson Werewolf Cover
Creepy #113, Nov 1979, Wrightson Tyrannosaurus Rex Cover
Frankenstein Illustration, Bernie Wrightson illo
Swamp Thing #7, Nov-Dec 1973, Wrightson Batman Cover