(23) Experts may also use technical imaging to visualise the physicality of the work, such as using X-rays for interior structure, infra-red imaging for
underdrawings, or ultra-violet fluorescence for restorations on the work.
New scientific analyses of the pigments and images, fresh paleographic evidence, and the resultant iconographic and thematic significance of what has been uncovered, strongly suggest that the scribe of the Pearl-Gawain manuscript, British Library, MS Cotton Nero A.x (art.3) and the person who made the
underdrawings of the miniatures (as distinct from their coloring) could have been one and the same person.
Visitors could view digital images of the
underdrawings and the surface, sliding back and forth to make comparisons in addition to looking at the paintings themselves.
A wheel from that bathtub-crashing-car drawing migrates to Canton Rose, 2016, while the nervous, glancing chicken and lunging insectoid caught between a wheel and a fan in two 2016 Untitled drawings seem to manifest as errant
underdrawings, or unconscious muscle-memory cartooning, amid the deep blacks of Earth Show, 2016, a painting dominated by a spacious and variably colored black bracket.
The realistic mode of these representations is described in detail (including the use of infrared reflectograms of some
underdrawings).
Cole acknowledges that Leonardo employed contour lines in the
underdrawings of his works.
A purpose-built camera with an infrared light source can "see through" the surface layer of paint to record
underdrawings and underpaintings that the artist may have initially rendered.
The art world has used infrared imaging since the 1930s to reveal drawings hidden under paintings, a technique that often works because the
underdrawings were done using black pigments made of carbon, such as charcoal.
Moreover, infrared photographs of the paintings, which revealed extensive preparatory
underdrawings, confirmed this surprising assessment.
In the introductory chapter (1-39), she explains that until 1505, Durer relied on substantial northern
underdrawings (17), that his abbreviating these in favor of preparatory drawings on "carta azzurra" (80) coincided with his one Venetian sojourn (18), and that his late work demonstrates how well he combined southern with northern Renaissance technique (19), unfolding how his postVenetian portraits continue to rely on minimal
underdrawings (23).