AIC's 52nd Annual Meeting

Water-soluble pencils and pastels have been produced and utilized since the early 1900s. Water-solubility, originally developed to aid in the clean-up of waxy graphic media, soon became a desirable property for artistic practice. As such, water-soluble graphic media was integrated into the works of Jackson Pollock, Sarindar Dhaliwal, Saul Steinberg and other artists’ collections. Due to the myriad of ways artists can apply this media, it can be challenging to visually distinguish it from their non-soluble pencil and pastel counterparts, as well as traditional watercolor washes. This is further impacted by the limitations of media labels, product data sheets, and the nature of artistic practice, which has made it difficult to track artworks made using water-soluble graphic media in collections. As previous studies have indicated, unlike traditional watercolor, water-soluble pencils can remain soluble long after they are applied due to their water-soluble waxy binder. The differences in their solubility behaviours paired with how easily they can be mistaken for other media can have dire consequences for artworks in collections. Additionally, there is little literature exploring the natural aging properties of these materials; therefore, the need for further exploration of these materials has been identified (Buttle Et al., 2015).

This research explores the composition, aging, and solubility behaviours of seven water-soluble graphic media: Caran D'Ache Neocolor II Aquarelle Water-Soluble Wax Pastels and Museum Aquarelle Watercolour Pencils; Brevillier's Cretacolor Aquarelle Oil Pastels; Derwent Inktense Ink Pencils; Faber-Castell Albrecht Dürer and Goldfaber Aqua Watercolour Pencils; and Gallery by Mungyo Watercolour Crayons. Fourier Transform Infrared (FTIR) spectroscopy, Pyrolysis-Gas Chromatography-Mass Spectroscopy (Py-GC-MS), and portable X-ray fluorescence (XRF) were used to identify the binder, bulking agents, and colorants. Preliminary analysis has indicated the presence of polyether-polyols and other sugars instead of traditional gum binders which may contribute to the media remaining soluble over time as previously described. Thermo-aging in hybridization tubes was undertaken on media that were applied to Arches Hot-press watercolor paper. A set of aged and unaged samples were then immersed in baths of commonly used paper treatment solvents: distilled water, ethanol, acetone, ethyl acetate and toluene. Any color shift resulting from these baths was monitored with a Konica Minolta CM-700d color spectrophotometer while the relative amount of media was tracked using ATR FTIR.

All research samples and data, in addition to pencil and pastel sets acquired will be added to Queen’s Artist Material Archive to support the development of a long term-natural aging study of these materials. An additional goal of the Artist Material Archive will focus on the creation of a database of External-Reflection FTIR spectra to help distinguish water-soluble graphic media from non-soluble pencils and pastels. This method will allow conservation professionals with access to FTIR to identify unknown media without damaging or sampling an artwork. This definitive baseline for future identification and material research will aid in the study of conservation concerns and treatment options for contemporary water-soluble pencils and pastels.