Synthetic organic colourants are extremely prominent in heritage collections, particularly throughout textiles. They are often generalized as highly light-sensitive; although, a broad distribution of lightfastness exists. This is evident in various fastness ratings published in late nineteenth century literature, the work of Schultz and Julius, and the Colour Index. In heritage conservation, much of the research related to light-sensitivity of dyed textiles has focused on natural colourants. This is likely due to a general interest in the dyes present on older objects, and the overwhelming selection of modern synthetic materials. To address this gap, a shortlist of targeted synthetic dyes was recently developed using census data for dye production and imports in the United States, and information gathered from the Colour Index. Our present work provides a follow up to the prior literature review, where a subset of samples from the published target list was used to evaluate lightfastness. To begin the study, a collection of dyed textiles from the last quarter of the nineteenth century was gathered from trade publications of the period, and those matching the target criteria were reserved for analysis. The lightfastness of more than 100 early synthetic dyes was then investigated using the historic materials. Test specimens were illuminated with a custom-built fadometer containing an LED light source that is characteristic of modern gallery lighting. Four batches of samples were exposed at 20 klx for approximately 6 months each, and diffuse reflectance was periodically measured with a portable spectrophotometer over white and black backgrounds. Measurements were taken at increasing light dose values to reach at least 85 Mlx·h per batch. Visible reflectance spectra were recorded in a dataset to document the colours as a function of light exposure, and foster future colorimetry research. Colour change was also calculated using the CIEDE2000 formula to assess lightfastness, and results were summarized as a resource to further develop risk analysis tools for exhibit lighting. In this paper, a detailed description of the test apparatus is presented with an overview of the lightfastness results and the resulting dataset. Comparisons are given with nineteenth century lightfastness data, and ISO values available in the Colour Index. It is hoped that the associated dataset will provide a foundation to be expanded over time with interest in further materials and test methods.

合成有机着色剂在传统系列中极为突出，尤其是在整个纺织品中。它们通常被概括为高度感光的；但是，存在广泛的耐光性分布。这在 19 世纪晚期的文学作品、舒尔茨和朱利叶斯的著作以及颜色指数中发表的各种牢度等级中很明显。在遗产保护方面，许多与染色纺织品的光敏性相关的研究都集中在天然色素上。这可能是由于人们普遍对存在于旧物体上的染料感兴趣，以及现代合成材料的大量选择。为了解决这一差距，最近使用美国染料生产和进口的普查数据以及从颜色指数收集的信息，制定了目标合成染料的候选名单。我们目前的工作是对先前文献综述的跟进，其中使用已发布目标列表中的一部分样本来评估耐光性。为了开始这项研究，我们从该时期的贸易出版物中收集了 19 世纪最后 25 年的染色纺织品集合，并将符合目标标准的那些保留用于分析。然后使用历史材料研究了 100 多种早期合成染料的耐光性。测试样本使用定制的 fadometer 进行照明，其中包含现代画廊照明特征的 LED 光源。四批样品分别在 20 klx 下曝光约 6 个月，并用便携式分光光度计在白色和黑色背景上定期测量漫反射率。在增加光剂量值以达到每批至少 85 Mlx·h 时进行测量。可见反射光谱被记录在数据集中，以记录颜色与曝光的函数关系，并促进未来的比色研究。还使用 CIEDE2000 公式计算颜色变化以评估耐光性，并将结果总结为进一步开发展览照明风险分析工具的资源。在本文中，对测试设备进行了详细描述，并概述了耐光性结果和生成的数据集。与 19 世纪的耐光性数据和颜色指数中的 ISO 值进行了比较。希望相关数据集将提供一个基础，随着时间的推移对进一步的材料和测试方法感兴趣。