Etcher writes Flint OS to SD Card and then card is empty and unreadable?

Trying to put Chrome OS (Flint OS) on my Raspberry Pi.
Bought a brand new Sandisk 32GB micro SD card today from a proper authorised shop, put it in my PC running Windows 10 64bit, formatted it using the SD card formatter, I then downloaded Etcher. I then download the Chrome OS file from choosing the Raspberry Pi version. When I open Etcher and select the image file and select the SD Drive and select Flash, the program does it’s thing and tells me that it is all done. When I try and open up the SD Card, windows doesn’t recognise the drive and doesn’t let me open the contents of the SD card. When I put it into my Raspberry pi it does nothing??? Have downloaded Win32DiskImager and tried this as well but the same thing happens, please can someone tell what is going on, have spent all day on this and getting nowhere.

From the Raspberry Pi Forum, it looks as though Flint OS is not supported on this new Raspberry Pi 3 B+ board. So will need to use a different OS.