“Hartgen is a landscape painter; his approach to nature is individual and dramatic. He is particularly successful in capturing fleeting impressions which he achieves with knowing simplification, freshness and striking limpidity of brushwork.
Maine forests, marshlands, coastlands, the sea and mountains offer Hartgen aesthetic experiences which he envelopes with imaginative intensity. Lyrical mood and formal unity embrace the structural vitality of his watercolors to delight the eye and to move the spirit toward independent artistic exploration. He balances harmony with eloquent expression and the utmost delicacy of feeling. His is a distinct contribution to the development of an American style of watercolor.”
~George Binet, gallery director, New York, 1947