His artistic output included icons, miniatures, triptychs and illuminated manuscripts, commissioned by both Catholic and Orthodox patrons.

Klontzas influenced Theodore Poulakis he created an extremely similar painting called In Thee Rejoiceth.

His triptychs strongly resemble the works of Gentile da Fabriano, namely the Intercession Altarpiece.

According to the Institute of Neohellenic Research fifty-four items of his art exist today.

He was also given the Greek Orthodox church of St Mark in the city of Candia (Herakleion).

The other painting was for the Catholic church of the welfare institution of St Anthony in Candia.

Klontzas became very popular his patrons included Orthodox and Catholic institutions, Greek bourgeois, and Venetian noblemen.

[6][7] A Venetian nobleman Francesco Barozzi born in Herakleion commissioned Klontzas to create two illuminated manuscripts for Giacomo Foscarini.

The codex features Biblical and prophetic texts ensconced with Byzantine and Ottoman history.

The Hyme is as follows: All of Creation rejoices in thee, O full of grace the angels in heaven and the race of men, O sanctified temple and spiritual paradise, the glory of virgins, of whom God was incarnate and became a child, our God before the ages.

All of creation rejoices in thee, O full of grace The Virgin is the central figure in the icon.

Klontzas painting style evolved into the complex use of figures which put the artist in a league of his own.

The maniera greca was common in Crete but Klontzas's paintings become saturated with figures.

Theodoros Poulakis in his second In Thee Rejoiceth does not cluster the figures as much as Klontzas and it may have preceded the similar work.

Klontzas's demon wolf-like figures depicted in The Last Judgement inspired many of Theodoros Poulakis dark creatures.

His most popular works include: In Thee Rejoiceth, The Last Judgement, Seventh Ecumenical Council, Christ Enthroned and Scenes from the Dodekaorton (Twelve Great Feasts), Sermon in a Church, and Battle of Lepanto.

A detailed manuscript map of the city of Candia with his son Maneas's signature also survives.