First Advisor

Tami Lasseter Clare

Term of Graduation

Summer 2021

Date of Publication

7-20-2021

Document Type

Thesis

Degree Name

Master of Science (M.S.) in Chemistry

Department

Chemistry

Language

English

DOI

10.15760/etd.7639

Physical Description

1 online resource (ix, 38 pages)

Abstract

Orotone photographs are positive photographic images on glass with a gold-colored metallic coating or backing. Although the materials and process used in the production of orotones have been previously documented, there is limited published scientific research on the subject. This study focused on expanding those published works by analyzing a greater number of photographs, including eleven orotones, four hand-colored orotones, two silvertones, and one uncoated orotone. The photographs, dating from the early to mid-20th century, were from the University of Washington (UW) Libraries' collection, except for one orotone that was from the Portland Art Museum.

X-ray Fluorescence (XRF) spectroscopy, Fourier Transform-Infrared (FT-IR) spectroscopy, Raman spectroscopy, Scanning Electron Microscopy/Energy Dispersive Spectroscopy (SEM/EDS), and Pyrolysis/Gas Chromatography/Mass Spectrometry (Py/GC/MS) were carried out to identify the materials used in the production of these photographic types. XRF analysis of the orotones revealed that copper and zinc alloys were used in the backing of all the orotones; silver was the imaging material of most of the photographs; there was sulfur and mercury toning of two images; some glass supports contained lead and arsenic; and other detected elements (e.g., potassium, iron, and bromine) remained from the photographic process. Py/GC/MS confirmed that one of the orotones had a gelatin emulsion and a previously unknown backing solution. The backing layer consisted of acrylate polymers and metal flake, which, given the presence of that unusual orotone polymer, may have contributed to the observed delamination of the emulsion and backing layers in that orotone. Analysis of the hand-colored orotones by XRF determined that vermilion and a possible mixture of cadmium yellow and a blue pigment were used as colorants. FT-IR and Raman analysis confirmed that Prussian blue was also used as a pigment. Lastly, XRF spectroscopy and SEM/EDS confirmed that an aluminum metal flake was used in the backing of a silvertone. Analysis of these photographs by a range of instrumental techniques helped increase the body of knowledge on orotones, hand-colored orotones, and silvertones, and this was possible from the collaboration between the Lasseter Clare Lab and the University of Washington Libraries.

Rights

©2021 Ivanny Jeannette Jácome-Valladares

In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).

Persistent Identifier

https://archives.pdx.edu/ds/psu/36316

Available for download on Thursday, July 20, 2023

Included in

Chemistry Commons

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