Does the cork or rubber side of the belt face the drum?

GE profile model # DPSQ475ETWW or ET0WW drum belt slipping.

Yesterday I took my dryer apart because it was not heating. I found the heating coil was broken. I bought a re-string kit, put it back together and now it works but sometimes when starting up with medium sized load of wet close the belt slips. I'm not sure if the cork or rubber side of the belt should be facing the drum.