For economical use of the diamond paste, use a BH4 or BH5 felt point that has been moistened with white spirit. The idea is to gradually impregnate the felt with the diamond paste over a period of use. Do not apply the paste directly to the article being polished or the rotating felt will scatter some of the paste over the workbench. Always retain a felt for the exclusive use of one grade of diamond paste. Each grade is colour coded to help prevent mixing one grade of paste with the other. After each use retain the felt point in a sealed bag to prevent it drying out.