Bleeding dyes are a major concern to textile conservators; they can cause extensive damage to textile objects and usually preclude a wet cleaning treatment. Since gel cleaning methods were introduced to the conservation field, new opportunities are available for such complex treatments. This paper describes the cleaning of an embroidered textile that is damaged by dye bleeding of the embroidery threads on an undyed silk ground. It was examined whether further bleeding of the dyes during wet cleaning can be avoided by the use of an agarose gel to deliver an aqueous solution, prepared with pH buffers and chelators, to the silk ground. Additionally, the siloxanes octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5) were tested for their potential to act as barrier liquids for the embroidered areas. The cleaning method was successful in preventing further bleeding of the dyes, but the coloured stains could not be removed completely by the compound cleaning solution. Further research is required to optimize the cleaning method.

The relationship between bibliographic and archival research, on the one hand, and object-based study, on the other, forms a very important basis for research into historical production techniques. Several written sources provide insight into the recipes for dyeing black in the past. Yet, this does not guarantee that these written recipes are representative of an entire society or were used in the dyers practice. The way to assess how closely practical dyeing and written sources are aligned entail the chemical analysis of historical textiles. This article focuses on the identification of the ingredients used to dye wool black in the case of well-preserved and dated (1650-1850) historical textiles from five Belgian archives and some remaining historical artefacts. The results are compared with the technical knowledge of dyeing and the ingredients mentioned in written sources from the same period. The aim is to refine the knowledge of the different black dye ingredients used in practice in Northwest Europe during the period.

This paper presents a historical analysis of a rare dyer’s manuscript, preserved within the Museum of Industry in Ghent, Belgium. The manuscript, originating from a dyer in late 18th-century Antwerp, includes an extensive collection of recipes. The study will enable researchers to better grasp the practices of traditional dyeing techniques and materials in the region during that time. The manuscript focuses primarily on the dyeing of woolen fabrics. Approximately 90 of the 132 recipes utilize red dyes. Recipes for dying orange, brown, black, blue, and green colors are also described. The document mentions the use of madder, brazilwood, redwood, and cochineal. To create a variety of red shades, the dyer describes how fabrics were treated with different mordanting compounds, with alum and tin as the main ingredients, and how the dyeing solutions were prepared. The resulting colors include ‘madder red’, ‘formal red’, ‘crimson’, ‘scarlet’, ‘Turkish red’, ‘fire color’ and ‘flesh color’. In addition to the dyeing recipes, the manuscript contains various accounting documents and correspondences between the dyer, customers, and suppliers. Lastly, over 100 original, colored samples are attached to the described recipes. In this paper, the artifact’s contents will be disclosed, comprising recipes with attached samples and correspondence. Findings resulting from archive research will be included, contextualizing and placing the dyer in their urban and social context. The paper concludes by discussing its potential limitations and provides avenues for possible future research.

Cleaning historical silk textiles is a particularly sensitive operation that requires precise control to prevent mechanical or chemical damage. In this study, we investigate using flexible PVA–borax-based gels to remove soot from silk, i.e., polyvinyl alcohol–borax (PVA-B) gels and polyvinyl alcohol–borax–agarose double network gels (PVA-B/AG DN) loaded with different cleaning agents—namely, 30% ethanol and 1% Ecosurf EH-6—in addition to plain gels loaded with water. These gel formulations were tested on simplified model systems (SMS) and were applied using two methods: placing and tamping. The cleaning results were compared with a traditional contact-cleaning approach; micro-vacuuming followed by sponging. Visual inspection, 3D opto-digital microscopy, colorimetry, and machine-learning-assisted (ML) soot counting were exploited for the assessment of cleaning efficacy. Rheological characterization provided information about the flexibility and handling properties of the different gel formulations. Among the tested systems, the DN gel containing only water, applied by tamping, was easy to handle and demonstrated the highest soot-removal effectiveness without leaving residues, as confirmed by micro-Fourier Transform Infrared (micro-FTIR) analysis. Scanning electron microscope (SEM) micrographs proved the structural integrity of the treated silk fibers. Overall, this work allows us to conclude that PVA–borax-based gels offer an effective, adaptable, and low-risk cleaning strategy for historical silk fabrics.

Treating silk with metal salts was a common practice starting in the second half of the 19th century until the early 20th century. It aimed to increase the weight and thickness of the fibres. However, the presence of metal salts is believed to accelerate and aggravate the deterioration of historical silk textiles, and weighted silks are nowadays considered one of the most pressing issues in textile conservation. This paper explores the history of the practice of metal salt weighting of silk: the materials and methods used, the reasons behind weighting, and how this practice developed as the product of a specific historical and economic context. A total of 147 primary textual sources (patents, dyers’ manuals, and books) were investigated and from these 136 weighting methods were collected and reviewed. The results highlighted tin salts as the most commonly mentioned metal salts for weighting silks of any colour. Iron compounds combined with tannins were the method of choice for dark silks, although also in combination with tin in half of the cases. The knowledge gained from this research will help further the study of the degradation pathways of historical silk fabrics, as representative reproductions of weighted silks will be produced based on the findings.