 By the mid 1970s Hollands use of visual metaphor, known by this point as "conceptual illustration", was so firmly established and pervasive that Op-Ed art director Steven Heller said that only 25 percent of Op-Ed artists knew the content of the articles their work was to accompany.In 1999, Holland and a small group of artists founded The Illustrators' Partnership of America (IPA).The initial goal of the IPA was to heighten artistic awareness regarding the growing influence of stock illustration houses, and how those businesses might potentially devalue art by offering art buyers the on-demand opportunity to purchase rights to art works for pennies on the dollar, compared to what they were previously accustomed to paying.