The paper is a contribution to the non-invasive identification of synthetic, semi-synthetic, and natural polymers of modern and contemporary artifacts and objects of historical interest.

The paper is focused on the identification of early plastics based on semi-synthetic polymers which were often used to imitate the more valuable natural materials.

A semi-automated procedure is proposed for the identification of unknown plastics based on non-invasive total reflectance (TR) FT-IR spectroscopic technique implemented by means of portable instrumentation.

A set of previously classified ten heritage objects were used as training set to corroborate the proposed procedure and to check its applicability to real objects.

The results show that (TR) FT-IR spectroscopy coupled with a custom reference library, specifically tailored for identifying plastics in collections, makes the classification of unknown samples possible.