Maentel is most notable for his watercolor portrait art that minutely portrayed the décor and dress of early American immigrant communities.
[4] While in New Harmony, Maentel painted the prominent Cooper, Jacques, and Faul families including triptychs on fireplace hearth screens.
Salvaged from the fire was book of "Materia Medica" handwritten to include a recipe for "Mental Salve," still singed and in a family collection.
A New Harmony Gazette entry notes the following: "Old man Mantle, one of Bonaparte's old soldiers died today [April 28, 1863] he was near 100 years old, born June 15, 1763.
[4][6] During his time in the militia, Maentel painted portraits of military officers and members of their families, backdropped by detailed home decorations, and typically showing them posed in the corners of well-furnished parlors.
Additionally, Maentel produced illustrations for marriage and birth certificates in the tradition of fraktur painting characteristic of the Pennsylvania Dutch community.
While the majority of portraits were painted in Southeastern Pennsylvania (Lancaster, York, Dauphin, Berks and Lebanon counties), It was later that the artist moved westward to Indiana where his work included fireplace screens and wall decorations.