The max thickness of the substrate you can print on varies by press type and manufacturer so you need to check with the manufacturer of the press you want to use. I’ve run plywood veneer - which is about the same thickness - through a Speedmaster 74.
I think 800 gsm is about 1.25mm or 0.05" thick?
This is not paper (commercial) but thick paperboard (folding carton packaging).
Is this solid paperboard or a flute corrugate?
Steve Suffoletto
I know a beverage coaster printer (www.katzamericas.com) that prints offset litho on 0.076" or 1.9mm paperboard.
I think their press is a Royal Zenith Planeta, now owned by KBA (Koenig & Bauer) as of 1991?
Steve Suffoletto