In the Grueby art pottery studio tasks were delegated according to talent and experience by company founder William Grueby. In the early years of the pottery, George Kendrick was responsible for design and production. As such, he supervised the throwers and modelers in the handmade and handcrafted production of Grueby Faience art pottery.
It is reported that Kendrick designed all early Grueby vases. Kendrick stayed with Grueby until around 1902. At that time, Addison Le Boutillier took over as the director of design for the pottery. In addition to responsibility for the design of Grueby vases, Le Boutillier is credited with development of Grueby tiles.
By 1906, Le Boutillier was replaced by Julia Harvey Bradley. Even though there was relatively consistent turnover in the leadership, it is commonly recognized by collectors and historians that throughout the history of Grueby Pottery there was a consistency in the arts and crafts style of the vases produced by the company. This consistency and commitment to the American Arts and Crafts Movement can only be attributed to the presence and overriding leadership of William Grueby.
Greuby Matte Green Vase 
Grueby Matte Green Vase
The modelers and potters who made the vases and tiles were given little public credit for their craftsmanship. While historic documents make it clear that Grueby valued their skill and the handmade and handcrafted art pottery, the company did not promote or seek recognition for individual modelers and decorators. As such, many Grueby Pottery modelers and artists have gone unidentified.
In addition to the Grueby trademarks often seen on the pottery, it is not unusual to find Grueby vases and bowls signed by the craftsman or modeler who created the artwork. In a random survey of approximately 500 examples of Grueby pottery, approximately 100 of the pieces were artist signed or initialed. Many of these initials have never been identified.
Some of the identified modelers or decorators at Grueby are listed in Marks of American Potters, 1904 and included the following:
Ellen Farrington, Florence Liley, Annie Lingley, Wilhelmina Post, Lillian Newman, Gertrude Priest, Maria Seaman, and Norma Peirce.
Unknown Artist 
Signed Wilhelmina Post
Many more Grueby vases have been signed by unidentified modelers. After all these years it is very unlikely the identities of these unknown craftsmen will ever be identified.
