This paper describes the adaptation and evaluation of three chemical tests for tannins characterisation in
vegetable tanned leathers. Tests were performed on fibres of new leathers tanned with different known
vegetable tannins and historic leathers. Rhodanine test, nitrous acid test and acid butanol test, developed
to identify, respectively, gallotannins, ellagitannins and condensed tannins, are described. Ferric test and
vanillin test, the two traditional tests used for vegetable tanned leathers characterisation, were also performed
and their usefulness discussed. Gallic acid, ellagic acid and catechin, structural constituents of the
different classes of tannins were also tested. Results of the developed methodology allowed the identification
of tannins’ chemical class in new and historic leather samples studied. Data obtained permitted
to verify the information on tanning materials used in new leathers. Vegetable tanning technology was
confirmed in historic samples and tannins were characterised. This study shows that these tests are useful
and can be a valuable source of information to evaluate new vegetable tanned leathers quality for
conservation and restoration purposes as well as historic leathers tanning technology