Drying is one of the most critical steps in the processing of latex into dry forms of natural rubber. Sheet rubber, which predominates the Indian rubber market, is conventionally dried in smoke. However, owing to various constraints, many small growers resort to at least partial drying in the open sun. In the present study different modes of sun drying are compared with smoke drying. The effect of ultra-violet light on the raw rubber properties has also been studied. It is observed that Po, Mooney viscosity and gel content increase while PRI decreases as a result of sun drying. The results indicated that unless exposed to sun for prolonged periods, the raw rubber and the breakdown properties are not affected significantly. A slight over-exposure of sheet to direct sunlight will not adversely affect the initial vulcanizate properties of the rubber but its ageing properties are found to be inferior.