Bertholet Illustrations was established in 2004 by Guusje Bertholet, a former lawyer who changed careers to become a specialist in medical and scientific illustration. She completed the highly respected course in scientific illustration given by the Rijksuniversiteit Limburg medical school and the Academy of Fine Art in Maastricht, and chose to continue her illustration career through her company.

Bertholet Illustrations is member of AEIMS (Assocation Européenes des Illustrateurs Médicaux et Scientifiques), the European association of scientific and medical illustrators and the Association of Dutch Designers.