He later published some other etchings of his portrait paintings .
In 1818 , Nicholson began publishing his Portraits of Distinguished Living Characters of Scotland , a series of etchings based on his own paintings and those of other artists ; it was not completed .
Nicholson later published some other etchings of Nicholson 's portrait paintings .
In 1818 , Nicholson began publishing his Portraits of Distinguished Living Characters of Scotland , a series of etchings based on his own paintings and those of other artists ; it was not completed .