The chemical identification of materials is the first step for developing and implementing recommendations for the care and display of resin cast and plastic objects in museum collections. This paper presents advantages as well as limitations of portable Raman. Therefore, a comparative analysis of portable and benchtop Raman instruments was performed in the study of materials found in the contemporary art collections of the National Museum in Krakow. The results of the Raman study were complemented with those obtained using Fourier transform infrared, near infra‐red, and gas chromatography mass spectrometry, in order to verify their accuracy. The results of this study showed that portable Raman spectroscopy is a suitable technique for the identification plastics in museum collections.