Isici
1. Ukugcoba okusebenzayo, izindleko zokuthambisa ziyingxenye yezinye izindlela zokugcoba.
2. I-lubricant encane, ukuvela kwegesi ephansi, kunciphisa ngempumelelo i-porosity yangaphakathi yokuphonsa (ikakhulukazi i-hydrogen stomata).