1.   A plate is fired after it is made, so the new paint would not last.

2.   It has to be painted, but the company says the paint will last longer than on wood, with a minimum of peeling.

3.   No paint will last that long.

4.   Touching up the sink with a porcelain touchup paint did not look good and the paint did not last.

5.   You will probably have to redo the sink periodically, although if properly applied, the paint will often last for years.