Materials in objects of cultural heritage (CH), such as paintings, span several molecular classes ranging from small molecules (mineral pigments and organic dyes) to polymers (proteins, polysaccharides, lipids, synthetics) used as binders, coatings, and adhesives. Characterizing these materials is essential to not only better understand and interpret the artist or maker, but to provide information that may serve to further identify manufacturing and artists’ techniques, clarify attributions, establish sourcing materials, and better preserve the work for future generations. Studying paint binding media and adhesives often involves studying proteins, which have been an important molecular class in objects of CH since the inception of art. These proteins, having numerous sources (eg egg, milk, blood, bone, skin, etc.),[1] have substantial effects on the appearance and stability of paints on canvas and paper paintings, and polychrome sculpture [2]. Despite recent advances in the understanding of proteins found in CH objects [3] their higher order structure (HOS), and the changes to the protein structure throughout its lifetime as an art material (ie from the egg, to mixing with pigments to create a paint, to drying to obtain a cohesive paint film, to paint making, drying in the paint, etc.), remains significantly understudied. HOS is directly correlated to the stability and function of proteins in objects and plays a pivotal role in the object’s integrity and preservation, but a critical hurdle to analysis is the ultra-precious nature of the objects, as well as the low abundance of proteins relative to the total sample.

The technologies used to elucidate the structure of materials in these objects are categorized as either invasive or noninvasive. Non-invasive techniques such as portable Fourier transform infrared (FTIR)[4] and Raman spectroscopy [5] are highly attractive because of their ability to extract molecular information without consuming the object’s precious materials. FTIR and Raman are well validated and remain gold-standards for pigment identification, and may be used to determine the localized presence/absence of proteinaceous materials on an objects’ surface. However, the interrogation of protein structures through these techniques remains limited due to the competing signals from other materials in the sample, as well as differential