Working under the gem-engraver Hermann Waldmann in Idar-Oberstein, Pennell began a long association with German and central European art and education.
He later developed a personal friendship and professional relationship with the Czech glass engraver Jiri Harcuba, as well as with teachers and students at the Prague Academy of Arts, Architecture and Design.
[2] On his return to England Pennell was appointed lecturer at Birmingham College of Art where he met his wife, Betty, and taught metal engraving, drawing and design.
Concentrating on developing his range, including bronze medallic art, Pennell refrained from exhibiting his work until 1974, when he was offered a solo show[4] organised by the newly restructured Crafts Council of Great Britain.
[5] Pennell also works as a sculptor, producing medals and reliefs in cast bronze,[7] examples of which are in the collections of the British Museum[8] and Goldsmiths' Hall in London.
He holds a Professorial Fellowship (from 1993) at the Academy of Arts, Architecture and Design in Prague, where he was also awarded the Gold Medal (1993) and the Highest Honour (1996).