This study handles the efficiency of sodium alginate polymer and sodium alginate nanocomposites for consolidating degraded papers dating back to 200 years. The paper samples were from wood derivatives. The characterization of untreated and treated papers was performed using SEM, ATR-FTIR analysis, XRD analysis for crystallinity estimation, pH measurements, and color change analysis. The study proved the positive effect of sodium alginate polymer for consolidating fragile papers. However, treated papers with SA polymer increased the pH towards an alkaline value, indicating that SA polymer was efficient in paper de-acidification; as the untreated sample recorded (p H 5.8), and the recorded measures for treated samples were 8.2, 8.4, 7.9, and 8.5. The surface morphology of SA alginate treated paper showed a strengthened structure because of the SA molecule self-aggregation, as the paper structure became more coherent and integrated. There is no color change could be detected by the human eye. Furthermore, the sample treated with SA/ ZnO gave (Δ E 0.87), but it was considered a slight difference, confirming that the zinc oxide had remarkable role in reducing the yellowness of the paper sample so it was recommended for consolidation treatments to enhance the performance of historical papers towards harmful effects of thermal aging.