Shipman, with wife Rhoda Shipman, created the independently produced comic book series Pakkins' Land, both plotting out the stories together and Gary scripting, lettering, penciling, and inking the illustrations for the series. Pakkins’ Land tells the adventuresome and engaging tale of Paul, a young boy who finds himself in a magical world filled with talking animals, mystery and excitement. Pakkins’ Land has been heralded for excellence by both critics and peers alike, accumulating an international following and numerous award nominations.

Certain characters in the Pakkins' Land stories are named after Shipman's children.

Shipman's artistic talents can also be found elsewhere. In 1987, he co-created the superhero character Edge for Silverwolf Comics, and illustrated the first 3 issues of that series.

In 1997, he illustrated the cover of Issue # 19 of the comic series OZ, based on the books and characters of L. Frank Baum.

In 1998, he illustrated the cover of Parables & Proverbs ISBN 0-9665118-0-8 published by New Creation Publications.

In 2003, he illustrated Amazing True Life Stories Issue # 2: Spymaster for Crosswind Comics.