hi – I use a two part epoxy resin very successfully to encase brass swarf in my jewellery. I tried to do it recently with some gorgeous bronze swarf that was a multitude of colours due to oxidation/heat. when the resin was curing all the colours vanished 🙁 I thought it may be the heat but I have tried pouring boiling water on some and the colours stayed. Any thoughts on a specific resin product or process that would protect the swarf would be appreciated