Physical Rubber prices witnessed weakness on Tuesday amid subdued demand for the commodity at domestic as well as overseas markets. Moreover, worries over a potential global recession and rising Covid-19 cases in China also weighed on rubber prices globally. Spot prices for RSS-4 variety declined to Rs 148/ kg compared to its previous closing of Rs 148.50/ kg; while the RSS-5 variety fell to Rs 144.50/ kg compared to its previous closing of Rs 145/ kg.