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Waxes as a component of seals, are recognized in our history as adhesives, for surface coating purposes, modeling or casting materials and also in conservation practice. The waxes with mineral, vegetable and animal origin should be connected to modern methods of analysis, due to their complex composition: long chain hydrocarbons, acids, alcohols, esters. They support many mechanical damages in library and archive collections: cracking, pieces lost by an excessive handling of documents. In this paper the compositional analyses of some wax seals belonging to some paper samples have been achieved by Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR) - for molecular structural information of wax materials, by gas chromatography / mass spectrometry (GC/MS) - for evidence of some compounds resulted from degraded wax seal, and by optical microscopy (OM) and scanning electron microscopy (SEM) - for visualization of the damaging effect on the wax seal. All these analytical investigations have been achieved for wax seals detached from the paper samples recovered from two disaffected pulp and paper factories - Letea and Busteni (Romania) belonging to Romanian industrial patrimony.

The paper focuses on two works of art, Chrysanthemums and Roses, painted by Stefan Luchian, a representative painter for the modern Romanian art from the beginning of the 20th century. The two paintings were analyzed by several non-invasive techniques (optical microscopy, grazing light and UV examination, IR reflectography, XRF and Raman spectrometry) in order to get information concerning the chromatic and to assess the state of conservation. The study is focused in particular on yellow, red and white pigments, which are different in the two pictorial compositions: in Chrysanthemums the predominant pigments are Madder lake, cadmium yellow and zinc white mixed with lead white, while in Roses cinnabar, strontium yellow and lead white were found, according to the XRF and Raman analysis.

Paper aging and protection processes play an essential function in the preservation of library collections and archives. In this study, some physical-mechanical properties of paper samples from XXth century books (private collections), such as pH acidity, tensile strength, and modulus of elasticity, as well as optical properties, such as absolute change in yellowness, were examined before and after treating them with hydroxyapatite nanoparticles (HAp). Accelerated light aging was also evaluated and discussed. The treatment with HAp nanoparticles increased the paper’s pH to slightly alkaline values (approximately pH 8). Washing and treating the paper improved its mechanical properties compared to untreated paper; the tear length increased by 35% and the modulus of elasticity increased by 56%. That the treated and aged samples are more elastic than the original samples demonstrates that HAp nanoparticles consolidated the cellulose fibers. Additionally, particle morphology, size, composition and size distribution were assessed via image analysis using scanning electron microscopy (SEM-EDX), atomic force microscopy (AFM), and the ImageJ processing program.