During conservation work in 1977 on the Column of King Sigismundus III Waza in Warsaw the old patina and the corrosive incrustation covering the metal parts were removed and replaced with an oxide layer. The thickness of this layer could be varied to give the required color. The oxide coating has better cohesiveness and mechanical and corrosion resistance than result from the use of traditional methods. See AATA 17-849 and 17-1615.