Material

The badge collection: materials and techniques

When it comes to insignia, attention quickly turns to the image itself. This is interesting and often crucial for identification. However, the material and technical aspects also teach us a great deal about this special collection. We are referring to the description, the material used and the production process.

Property description

Badges are small, lead-tin pins. They were usually worn on hats. That is why they are only beautifully finished on one side. Some badges have a pin on the back. Others have eyelets for sewing them on. On many badges, these fastening mechanisms have disappeared. These are small, fragile elements that break off very quickly.

Today, the badges appear grey and dull. Once upon a time, the metal shone and the badges sparkled as if they were made of silver. On the back, some badges have a flap behind which a piece of paper, fabric or parchment could be attached as a background. This creates a greater contrast, making the image stand out better. Some badges are also decorated with glass beads or imitation gemstones. Occasionally, traces of paint can also be found.

The fact that badges today appear almost black is due to “tin pest”. This is a chemical reaction in which the crystal structure of tin changes at low temperatures. This causes discolouration from “white” to “grey” and embrittlement. As a result, the material breaks much more quickly. The lead alloy slows down this process. However, after several centuries in the ground, they still turned black and dull.

Production process

Casting is the most common production technique. The badge is carefully carved out in a casting mould (also called a die or mould). The molten metal mixture is poured into this mould. Once solidified, it can be removed from the mould. The excess metal is cut off and the badge is ready.

The mould usually consists of a fine-grained, soft type of stone, such as limestone. This allows for detailed carving. However, moulds made of bronze, wood, horn and even whale bone have also been found in Europe. Unlike stone moulds, these moulds can only be used once. Recovered casting burrs and a single casting mould indicate that insignia were also produced in Yper.

There is also a disadvantage to this new technique. It cannot be used to make badges with openwork frames. The badge of the Ghent Altarpiece is cast and has an openwork frame. There is even a small open space between the two front legs. On Kunera, the badge database, we also see a Ghent Altarpiece, but here it is stamped rather than cast. It is a thin plate made entirely of metal.