There is a growing need and special attention for using textile products to provide effective protection against such damage of UV-radiation, i.e., skin cancer, sun burn, and photo-aging, in the recent years. In this research work a new approach for upgrading the UV-protective properties of cotton/wool and viscose/wool blended fabrics for high quality/trans seasonal apparel, was investigated. Factors affecting the UVB-protection function of the aforementioned substrates such as type and concentration of finishing additives, as well as subsequent treatment with cu-acetate or dyeing with anionic or cationic dyes were studied. The experimental data show that: i) the enhancement in the UV-protection factor (UPF) of the finished fabrics is determined by the type of finishing additives, i. e., citric acid >= aspartic acid >= tartaric acid >= none, chitosan TEA. HCL >= choline chloride >= none, beta-cyclodextrin CMC-30 PEG-600 > none, and Siligen (R) WW > W Siligen (R) PEP >= Leomin (R) NI-ET >= none, regardless of the used substrate, ii) UPF values are governed by the type of substrate, i. e., viscose/wool > cotton/wool, irrespective of the used additives, iii) post- treatment with cu- acetate or post- dyeing with the used dyestuffs brings about a dramatic improvement in UPF values, and iv) UPF values are determined by the finishing regime and follow the descending order: Resin finishing -> post dyeing > resin finishing -> posttreatment with Cu- acetate > resin finishing in presence of additives > resin finishing in absence of additives.