This was further cemented when Mannin became a salaried employee of the Society in May 1756 as the master of the school of ornament, a post he would hold until just before his death.
During his tenure, he taught many Irish artists such as John James Barralet, George Mullins, and Thomas Roberts.
The Society was interested in the development of art education in France, and purchased prints after works of French artists to be used as teaching aids.
He also taught art privately, and even complained in an address in June 1766 that the Dublin Society's teaching demands encroached on his ability to pursue this work.
[1] He became ill in early 1779, leading him to suggest Barralet to be appointed master of the school of ornamental drawing in his place.