Challenges encountered during acid resin transfer preparation of fossil fish from Monte Bolca, Italy

Abstract

Five specimens of fossil fish from the Eocene deposits of Monte Bolca, Italy, were selected for preparation by the resin transfer method. The specimens were set in a synthetic resin, leaving the base exposed, and acetic acid was utilised to remove calcareous matrix from the exposed side. The specimens, of diverse genera, were obtained from various collectors from 1847 to 1933 and were therefore of both historical and scientific interest. The matrix blocks containing each fish were known to have been originally adhered onto supporting slabs of the same matrix with an unknown resin, and the joins concealed with a mortar. This paper records successful outcomes, and documents various challenges encountered during the preparation process, together with an account of the materials and techniques utilised. Due to the poor performance of the embedding resin initially chosen, a brief overview of resin types and trials of some of the commercially available alternatives is included.