A detailed engraving by Dominicus Custos portraying Gian Giacomo de Medici within an elaborate architectural frame, showcasing period military attire and ornamentation.

This engraving by Dominicus Custos depicts Gian Giacomo de Medici, the Marchese di Marignano, positioned within a highly architectural frame. The subject is shown in profile, wearing armour and holding a circular shield, which draws inspiration from the classical tradition of military portraiture. His stance, with one leg forward, suggests movement, while his gaze remains fixed towards the left of the composition.

The surrounding frame is characteristic of the late sixteenth and early seventeenth-century print tradition. It features elaborate columns adorned with relief carvings of putti, fruit, and foliage. The upper section includes military motifs, such as cannons and weaponry, which reinforce the subject's status as a commander. Below the central niche, a cartouche contains the Latin inscription: Joannes Jacobus medices marchio meliani. The precision of the line work demonstrates the technical skill of Custos, a printmaker who was active in Augsburg and known for his contributions to portrait series and historical documentation.

Custos utilised a variety of hatching techniques to define the textures of the metal armour, the soft fabric of the sash, and the stone-like quality of the architectural niche. The depth of the scene is achieved through the use of shadows within the archway, creating a sense of three-dimensional space. This print reflects the period's interest in combining portraiture with decorative, symbolic elements that communicate the subject's identity and professional achievements. The work is an example of the high level of craftsmanship found in European printmaking during this era, where the marriage of portraiture and ornamental design was common in the production of commemorative volumes and biographical collections.