This paper will present the results concerning the use of new material as a consolidant and/or colour protector. A specific polysaccharide material extracted from the prickly pear (Opuntia ficus indica) has been tested on modern papers and historical materials. An ancient book (18th-19th century) was chosen as historical material. Before applying the polysaccharide material, a conservation-restoration preliminary treatment was carried out on the book's pages: sampling, fibre analysis, dry cleaning, ink solubility, pH test, thickness measurement, and wet cleaning. The polysaccharide material was then applied with different techniques, and the treated sheets were analysed by FTIR-ATR. In the second part of our work, we decided to use the mucilage extracted from Opuntia Ficus Indica to test its use as a colour fixative. Thus, the procedure involves removing impurities with wet cleaning, with the sample wholly immersed in water. This cleaning is the best method for removing contaminants from the paper or fabric backing, it can be used on paper or objects painted in watercolour. The material was applied in different ways (with extraction in alcohol and solid form by means of a spraydryer in various percentages with sericin), and a physico-chemical characterization was carried out by FTIR-ATR and SEM analyses. The results gave excellent evidence of the protection of colours sensitive to aqueous treatments. Therefore, applying this material can be suggested as a new cleaning method for water-soluble materials.