This book gives the Physical Chemistry Principles of the effectivenss of security features of different Universal Paper Banknotes upon modification by CMC and accelerating ageing. It clarifies the CMC addition effect on the security features involve secure complex process such as watermark, security thread, micro printing,etc. of different banknote papers (Egyptian 5 pounds "EGP", Egyptian 10 pounds "EGP", 1 Riyal "SAR", 5 Dirham "AED", 1 Dolar "U$", 5 Euro "€") even after accelerated ageing; thermal ageing at 140 °C for 2 hours and UV-radiation ageing with two different wavelengths (l1= 256 nm, l2 = 336 nm) through transmitted light, IR and UV-light. From this book,we concluded that CMC modification has no effect even small on paper Banknote security features which elucidate in turn that the effectiveness of security features within Banknote papers is marvelous after CMC addition. This pointed out that CMC coating is a major industrial operation used to improve appearance, strength properties and printability of paper. It can be concluded that paper CMC modification has wonderful reflection on the industrial side in the paper industry field.