What is the hardness of gravure chromium to the printing standard?

Inquiring about the carton net, we know that the scraper is iron, while the intaglio is chrome-plated on the surface of the copper tube. Because the hardness of copper is 200 ~ 300 HV and the hardness of chromium is 700 ~ 900 HV, it is best to choose a scraper with hardness of 450 ~ 600 HV, which will not damage the printing plate and will not easily leave knife marks.