Portrait of Dante

surface prep

The canvas must be stretched tightly and sized with animal glue (rabbit-skin glue) to prevent the tempera from soaking into the fibers. It is then coated with multiple layers of gesso (chalk mixed with glue) and sanded smooth. This preparation is critical for tempera, which requires a non-absorbent, white ground to achieve the luminous, opaque quality characteristic of Botticelli’s work. The smoothness allows for the 'minute visual expression' and fine line work that defines the artist’s style (Source 4).

underdrawing

Botticelli was primarily a draftsman, and his paintings are underpinned by a highly finished drawing. The underdrawing should be executed with charcoal or black chalk, focusing on 'minute visual expression' rather than just scientific accuracy. The lines should be confident and expressive, capturing the 'emotional significance' of the subject. As noted in sources regarding Botticelli’s studies, the drawing must be 'as highly finished as hard application can make them' to ensure that the subtleties of form are instinctive before paint is applied (Source 4).

underpainting

In tempera painting, there is typically no separate 'underpainting' phase in the oil sense (like an imprimatura). Instead, the white gesso ground acts as the light source. The artist begins by laying in the mid-tones and shadows directly with thin, transparent layers of tempera. This builds up the form gradually. The technique relies on the opacity of the white ground showing through the thin glazes to create highlights, rather than mixing white into the paint for lights.

Law of Contrast

Used to select background and drapery colors that complement the sitter’s complexion, enhancing the portrait’s impact. The artist must avoid 'crudity' by using light tones or grey-mixed colors if intensity is too high (Source 1).

Chiaro-Oscuro

Applied through the juxtaposition of light and dark tones to create depth and form. The gradation of light is achieved by the interaction of adjacent tones, not just by shading (Source 2).

Expressive Drawing

The underdrawing is highly finished and expressive, capturing the 'emotional significance' of the subject. This is a hallmark of Botticelli’s style, where drawing is not just preparatory but integral to the final effect (Source 4).

Tempera Glazing

Building up form through thin, transparent layers of pigment mixed with egg yolk. This allows for luminous colors and precise details, characteristic of Early Renaissance painting (Source 6).