Exsperiments of making rubber compound for canvas shoe sole and foxing have been done by varying filler (MgCO3). Composition used for rubber compound is : pale crepe 100 parts; MgCO3 30 parts; CaCO3 75 parts; ZnO 10 parts; stearic acid 0. 5 part; napthenic oil 2 parts; paraffin wax 0. 5 part; titanium dioxide 10 parts ; AOSP 1 part; MBT 0. https://www.markbroyard.com/super-value-krowne-18-x84-back-bar-drain-board-and-sink-sale-limited-save/