The recent conservation and restoration phases of The Ghent Altarpiece have astonished scholars and the public alike by revealing the exceptional original brushwork of Jan and Hubert van Eyck. Yet some of the polyptych’s most intricate and enigmatic features remain under investigation: the applied brocades that form the richly decorated cloths of honour behind the Deity, the Virgin, and John the Baptist. To imitate the lustre and texture of luxurious silk and gold-threaded fabrics, the Van Eycks employed a highly sophisticated gilded tinrelief technique. These brocades, now heavily overpainted due to early degradation, present substantial challenges for conservation while offering a rare opportunity to study one of the few surviving prime examples of this demanding method. An extensive multimodal analytical campaign was undertaken to (a) identify remaining original metalrelief areas within surfaces repeatedly impacted by past interventions, (b) characterise the materials and layer stratigraphy, (c) document the current state of conservation, and (d) elucidate ongoing degradation mechanisms. Non-invasive analyses on the panels included upright and stereo microscopeaided visual examination, Macroscopic Xray Fluorescence (MAXRF) imaging, and Macroscopic Xray Powder Diffraction (MAXRPD). Complementary microanalyses on sampled material involved Field Emission Gun Scanning Electron Microscopy with EnergyDispersive Xray Spectroscopy (FEGSEMEDS), Fourier Transform Infrared Spectroscopy (μFTIR), MicroRaman Spectroscopy (μRS), Optical Photothermal Infrared Spectroscopy (OPTIR), and Synchrotron Radiation-based micro Xray Powder Diffraction (μSRXRPD). This study has directly informed ongoing treatment decisions and significantly advanced insight into the Van Eycks’ innovative metalrelief technique—one of the earliest and most refined examples in European painting.