In this context, the drawing represents any figure drawn using graphic lines, engravings or affixes on a support. Since it can be made with simple means, it allows the artist to develop a personal technique and offers ample space for experimentation, becoming the most direct and sincere expression of his thought. Depending on the level of detail and complexity, the drawing has been described in various ways in the artistic treatise (sketch, sketch, model, sketch). 

The motif of the bird tied to a string is found in a study of the Cini Foundation in Venice that could be preparatory for the Madonna del Passero.

Look for corrections, afterthoughts and regrets in the main IR image on your left.

The modus operandi of Barbieri is mainly based on a direct drafting of color, almost abandoning the technique of preparatory drawing, limiting itself to short, thin, not continuous and half-dry strokes for the realization of the contours of the face. The same trait is also visible in the anatomical details of the face, such as eyes, nose and mouth, and in the hairline.

A fluid medium brush is, instead, used by Guercino in some steps, to create an artifice aimed at «detaching from the bottom» certain elements, in order to bring them into the foreground, in a sort of three-dimensional treatment. This is visible in the profile of the left arm of the Child

There are small corrections, shots and modest repositioning performed in order to respond to its own aesthetic perception or greater anatomical accuracy. This is evident in the repositioning and/or scaling of the knee and foot of the Child and in the index finger of the Virgin.

The electromagnetic radiation that our eye can detect falls within a range of wavelengths, (“visible light”), from about 400 to 750 nanometers. Beyond these limits, the radiation becomes invisible to humans, but it still can interact in various ways with matter, e.g., through absorption, reflection, transmission, similar to what happens with visible light.

Infrared reflectography is an image acquisition technique that exploits the ability of infrared radiation (wavelength of near-infrared radiation 800-1000 nanometres) to penetrate below the surface of paint and visualize compositional paint changes. By taking advantage of this property, it is possible to observe – where present- preparatory  sketches underneath the pictorial layer or to reveal pentimentos (afterthoughts, regrets) or to study changes made by the artist. The images that can be obtained are greyscale, where the lightest areas are those with chemical-physical characteristics that reflect infrared radiation either to a larger extent or completely. The sensitivity of the analysis depends not only on the chemical nature of the paint layers but also on their thickness. Infrared reflectography is pivotal in order to study the painter’s technique and the ‘idea’ at the origin of the painting: it is possible to observe elements that are not visible to the naked eye and to provide information on the evolution of the composition and construction methods of the artwork.