The main purpose of surface treatment/coating on magnets?
* Corrosion resistance
* Color decoration
* Abrasion resistance
* Increase glue ability
* Increase mechanical strength

The available coating types with X-MAG,
* Ni-Cu-Ni
* Ni-Cu-Epoxy
* Parylene
* Ni-Au
* Zn
* Everlube
* PTFE (Teflon)
* NiP (Chemical Nickel?
* PVD AI 
* HDPE
* ABS
* LLDPE
and more

How to correctly choose the surface treatment/coating for a magnet?
When you choose coating for the magnet, the below factors of coating should be taken in to consideration.
* Colour
* Layer thickness
* Cost level    
* Heat resistance ability    
* Corrosion resistance ability in humidity water    
* Corrosion resistance ability in salty air/salt water    
* Glue ability
* Abrasion resistance