The first step in the analytical process is to fully document and photograph any relevant features that are characteristic for the early hilt-plate blades such as the hilt plate, hilt outline, the rivets, cross-section and decoration. Additional attention is paid to any traces of its manufacture such as how the blade may have been cast, sharpened or repaired. For example, there are distinct differences in how the hilt-plate or rivets are shaped. The rivet holes are of further interest because they can be cast, punched or drilled. Each feature may be a helpful indication towards detecting craft traditions and workshops and support the chemical and isotopic data towards their identification.
Sampling and restoration
After documentation, a small sample is taken with a 1,5 mm drill to extract up to 50 mg of uncorroded metal in the form of bronze chips. In general, a sample is taken from the thickest and most solid part of the blade. Additionally, the rivets are sampled to determine whether the blade and rivet were made from the same or a different material. Afterwards, each sample location is sealed to restore the artefact to its original appearance. This is done with microcrystalline wax with various pigments to match the colour of the wax with patina of the artefact. The added benefit of a wax seal is that it prevents renewed corrosion and it is reversible.
Examples of restored blades and rivets