Dürer, who for decades made use of the same draughtsmanly ‘toolbox’ for constructions, was also apparently able to develop his schemata dynamically. Unusually, in the Vienna Portrait of a Young Venetian Woman, which in no way resembles the other Venetian lady held in Berlin, the grid of nine fields is tilted.
The lines running upwards to the left corner are arranged parallel to one side of a triangle that touches the cheek of the unknown sitter. A further side of the triangle lies exactly on the chin line of the linear grid, whereas the upper line runs precisely through a point of intersection along the hairline.
In this painting it can be presumed that first the straight line along the cheek and the complete triangle were conceived from edge to edge of the image before Dürer laid out the grid to structure the face and upper head.
As a rule, the first step has to be the production of a central vertical along which the Vitruvian tripartite division is then carried out. (This creates six fields, to which three more have to be added on the right-hand side in the case of a three-quarter profile.)
Frequently there are indications of where this central vertical begins and ends or through which points it runs. But in the case of the Venetian woman in Vienna there is only one discernible place: the corner of the eye at the bridge of the nose. The line along the cheek, however, targets exactly a point along the edge of the image that marks the white ribbon on the reddish dress.
The Portrait of a Young Man in Berlin also ‘functions’ differently. The construction of the schema must also have begun with a line that first established the averted side of the face.
This line was also expanded into a scalene triangle, which connects the right-hand edge of the image with the upper edge of the blackened background.
On top of the triangle Dürer added a diagonal proportional diagram with nine fields. At two points, lines converge or intersect: important is the point of the chin, for there the determining of the three equal parts of the face length begins. Additionally, points of intersection also occur at the height of the beret’s brim as well as at the collar just below the jaw-length hair.
For the interior schematising, quite a number of compass sweeps with the radius of the interior circle were used. From various starting points, they structure the face and hat.
 Levey discusses a connection of both Venetian women to Giovanni Bellini: Michael LEVEY, Minor Aspects of Dürer's Interest in Venetian Art, in: The Burlington Magazine 103 (1961), S. 510-513.