I am submitting art to be offset printed on aerosol cans and plastic tubes. It uses 2 PMS colours. One plate is a 100% flood. The other one is a linear gradient from 0% to 100%. The gradient is to be overprinted on the 100% flood. The maximum density will be 200%. This is the way the boxes are printed, and it looks great.

![enter image description here](https://i.stack.imgur.com/2ez46.png)

Can overprint be used on metal containers (aerosol cans) or plastic tubes? Since the material is way less absorbent than paper, I am worried that the ink might start moving around if the density is too high.

I know I can ask my manufacturer, and I did, but they are in China and, although they are a very seasoned manufacturer, I am having a hard time communicating the overprint concept to them. I was wondering if it is because it is not possible to use overprint on these materials, so nobody ever asks for it.