C. Olives and al. 2025
The inkwell also includes traces of ink, something extremely rare in archaeology. The paint recipe is also particularly notable for mixing two different techniques.
One small bronze inkwell discovered in the Roman city of Conímbriga, in central Portugal, is revealing new information about the writing practices of the Roman civilization.
The discovery, detailed in a new publication in the journal Archaeological and Anthropological Sciences, is the first of its kind in the Iberian Peninsula and is one of the rare archaeological examples to preserve ancient paint residues.
The inkwell, identified as a Biebrich-type vase from the early 1st century AD, was unearthed near a layer of landfill associated with the demolition of the city’s amphitheatre, suggesting that its owner may have state involved in public works or administrative supervision.
Made from an alloy of bronze with copper, tin and lead, the 94-gram container is a example of Roman metallurgical techniques more advanced. Its cylindrical shape, decorated lid and central opening are similar to inkwells that were frequently used in military and bureaucratic contexts in northern Italy and the Rhine region, explains .
But the most remarkable discovery was inside. Sediments removed from the container retained microscopic traces of old paintsomething that is extremely rare in archaeological studies. Advanced analytical techniques, including gas chromatography-mass spectrometry, nuclear magnetic resonance and X-ray analysis, revealed that the ink had a complex and much more sophisticated recipe than expected.
The researchers identified amorphous carbon produced by burning pine or spruce wood, along with bone black derived from the calcination of animal bones. The iron compounds characteristic of ferrogallic paint were also present, marking a unusual combination of two technologies of different ink. Beeswax and animal fat were added to stabilize the mixture and improve adhesion to the papyrus or parchment.
This hybrid formulation, known as “mixed paint”is rarely documented archaeologically, despite ancient textual references. Its presence at Conímbriga suggests that Roman scribes and artisans experimented with multi-ingredient recipes earlier and over a wider geographic area than previously believed.
The discovery reinforces Conímbriga’s reputation as a literate Roman city with administrative importance. Writing instruments rarely survive, but various other evidence of literacy, such as stamp boxes, wax tablet scrapers and other inkwells, have been discovered several times at this archaeological site.
