Paint Components

Zinc White Paint Issues

Zinc oxide is a pigment commonly used in 20th century oil based paints. It reacts readily with fatty acids found in oil to form degradation products such as zinc carboxylates, zinc carbonates and zinc sulphates. These, in turn, have effects on the paint films in which they form, resulting in various visible phenomena such as zinc soap protrusions (containing mainly zinc palmitate and zinc stearate), severe delamination of upper paint layers (when the lower layers contain zinc protrusions and cause separation between the layers), flaking and brittleness of paint layers (where the paint layers have high concentrations of zinc soaps within the oil paint matrix), and efflorescence (where a layer forms on the surface of the paint consisting of palmitic and stearic acids.

Related Phenomena
Delaminating
Flaking
Lifting
Efflorescence
Protrusions/Aggregates

Zinc White Paint Issues

Winter, G., Whittem, R.N., Fluorescence and photo-chemical activity of zinc oxides, 1950, in: Journal of oil colour chemical association 33 (nov), pp 477-483

van der Weerd J., Geldof M., van der Loeff L.S., Meeren R.M.A., Boon J.J., Zinc soap aggregate formation in 'Falling Leaves' (Les alyschamps) by Vincent van Gogh, 2003, in: Kunsttechnologie Konservierung 17(2), pp 407-416

Osmond, G., Keune, K., Boon, J.J., A study of zinc soaps found in paintings at the Queensland Art Gallery, 2005, in: AICCM Bulletin 29, pp 37-46
https://www.researchgate.net/publication/276385362_A_study_of_zinc_soap_aggregates_in_a_late_19th_century_painting_by_RG_Rivers_at_the_Queensland_Art_Gallery

O'Donoghue E., Johnson AM., Mazurek J., Preusser F., Schilling M., Walkton MS., Dictated by media: Conservation and technical analysis of a 1938 Joan Miró canvas painting, 2006, in: Studies in Conservation 51(2), pp 66-68

Rogala D., Franz Lake S., Mains C., Mecklenburg M., Condition Problems Related to Zinc Oxide Underlayers: Examination of Selected Abstract Expressionist Paintings from the Collection of the Hirshhorn Museum and Sculpture Garden, Smithsonian Institution, 2010, in: Journal for the American Insititute of Conservation vol. 49 (2), pp 96-113

Osmond. G., Ebert, B., Drennan J., Zinc Oxide-centred deterioration in 20th century Vietnamese paintings by Nguyên Trong Kiêm, 2014, in: AICCM Bulletin 34, pp 4-14
https://aiccm.org.au/sites/default/files/docs/Bulletin2014/BulletinVol34/6932%20AICCM%20Bulletin%20v34-osmond.pdf

Helwig K., Poulin J., Corbeil M.C., Moffat E., Duguay D., Conservation issues in several twentieth-century Canadian oil paintings: The role of zinc carboxylate reaction products, 2014, in: Issues in Contemporary Oil Paint, pp 167-184

Osmond G., Zinc White and the influence of paint composition for stability in oil based media, 2014, in: Issues in Contemporary Oil Paint, pp 263-281

Keune K., Boevé Jones G., Its surreal: Zinc oxide degradation and misperceptions in Salvador Dalí's Couple with Clouds in their Heads, 1936, 2014, in: Issues in Contemporary Oil Paint, pp 283-294

Hermans J.J., Keune K., van Loon A., Iedema P.D., An infrared spectroscopic study of the nature of zinc carboxylates in oil paintings, 2015, in: Journal of Analytical Atomic Spectroscopy vol. 30 (7), pp 1600-1608

Campos M.F., Carlyle L., Melo M.J., Beneath the surface: paint losses due to zinc soap formation within ground layers from a late 19th century oil painting, 2016, in: Metal Soaps in Art: Conservation and Research,
https://www.researchgate.net/publication/326838736_Beneath_the_surface_paint_losses_due_to_zinc_soap_formation_within_ground_layers_from_a_late_19th_century_oil_painting

Campos M.F., Carlyle L., Melo M.J., Zinc soap formation aligned with wood grain pores on two late 19th century oil paintings, 2016, in: Metal Soaps in Art: Conservation and Research,
https://www.researchgate.net/publication/326838886_Zinc_soap_formation_aligned_with_wood_grain_pores_on_two_late_19th_century_oil_paintings