The article focuses on the analysis of blotting sands found in Portuguese Inquisition documents from the period of 1551-1800. Blotting sands were used to hasten the drying process of ink by increasing the liquid ink surface area. The study conducted by researchers M. Nunes, G.W. Martins, J. Sarraguça, F. Olival, and P. Moita utilised a combination of image analysis, SEM/EDS, and μ-Raman techniques, along with statistical and chemometric analyses, to characterise the blotting sands.
The findings of the study revealed that the sands were predominantly medium-sized, well-rounded, and composed mainly of Fe-Ti and Fe oxide minerals. These characteristics indicated a texturally mature sediment, likely originating from fluvial or beach contexts and processed later. The research also uncovered a significant correlation between the morphology and composition of the sands from different time periods, suggesting the use of similar blotting sands over time.
The choice of black sands for blotting purposes was likely influenced by factors such as proximity to sources, reduced costs, and aesthetic considerations. The concentration of heavy minerals in the samples indicated the use of processing technologies like sieving and panning during the preparation of the blotting sands.
Overall, this study represents a groundbreaking step in understanding the intricate writing tools used in historical contexts, particularly during the prevalence of iron gall ink. The research not only contributes to the knowledge of historical writing materials but also opens up possibilities for developing conservation strategies for written heritage. The findings highlight the importance of studying and preserving these artefacts for a deeper understanding of historical practices and materials.