The distilled water productivity of the single basin solar still is very limited. Some methods have to be developed to improve this productivity. Using black rubber or black gravel materials within a single sloped solar still as a storage medium is examined in this work. To study experimentally the effect of different parameters such as rubber thickness and gravel size under the same operating conditions, four identical still units are designed and constructed. The experimental results showed that black rubber (10 mm thick) improves the productivity by 20% at the conditions of 60 l/m(2) brine volume and 15 degrees glass cover angle. Also, using black gravel of 20-30 mm size improves the productivity by 19% at the conditions of 20 l/m(2) brine volume and 15 degrees of glass cover angle.