Prices of spot rubber improved on Tuesday. RSS 4 firmed up to ₹109(₹108) a kg, according to the traders. The grade was quoted at ₹108 (₹106) and ₹105 (₹103) respectively by the Rubber Board and dealers. March futures improved to ₹106.75 (₹105.03), April to ₹109.20 (₹109.11), May to ₹111.36 (₹111.22) and June to ₹113.01 (₹111.75) on the National Multi Commodity Exchange. RSS 3 (spot) slid to ₹99.91 (₹100.01) at Bangkok. March futures closed at ¥160.5 (₹95.77) on the Tokyo Commodity Exchange. Spot rubber rates ₹/ kg were: RSS-4: 109 (108); RSS-5: 107(105); Ungraded: 103 (100); ISNR 20: 103 (100) and Latex (60% drc): 78.50 (76).