"[1] An exhibit review by Seattle Times art critic Robert Ayers described his impact by declaring "Gregory Blackstock is one of our city's greatest artists.

[3] Art critic Robert Ayers described Blackstock's "cheerful" work:[2] [It] would not be too much to claim this self-taught 66-year-old as something of a living civic treasure — an Audubon for our time and place.

Blackstock's art, much like the great naturalist's, is founded on detailed observation, comparison and categorization, but whereas Audubon was able to occupy himself for years with his monumental "Birds of America" project, Blackstock reflects the contemporary world's demand that we make sense of many unrelated things at once.The subjects of his paintings include examples of plant and animal life; tools, buildings, and vehicles; and other eclectic categories such as stringed instruments or mariners' knots.

[10] Blackstock researched topics at his local library, making use of reference works like encyclopedias to learn details about each subject.

[6] British art historian Roger Cardinal noted the "autistic repetition" of Blackstock's art, claiming "[his] work represents a kind of stocktaking, the reflection of a yearning for order and perhaps ultimately of a longing for mastery over the unthinkable subtleties of our shared world — a desire for supremacy as chief overseer of reality's infinite variations.

[12] Beginning in 2012, Blackstock was represented by Greg Kucera Gallery in Seattle, which featured him in several single-artist and contextualized thematic exhibitions.

In 2021, an exhibit titled "The Incomplete Historical World, Parts I, II & III" featured limited-edition prints of his work which were a collaborative project between the artist, his family, and Greg Kucera Gallery.

[15] Some of his images were used for haute couture clothing by Comme des Garçons, and others were sold as greeting cards and jigsaw puzzles.

[6] A book of his work was published by Princeton Architectural Press in 2006 titled Blackstock's Collections: The Drawings of an Artistic Savant.