The website of Real Russia states:
There are two main formats of visa being issued by Russian consulates at the moment (in addition to the rare separate paper version)
As does the website of RSPB Travel:
A Russian visa is a special document either stamped to your passport or issued on a separate paper, that grants you a permit to enter and to leave the Russian Federation during a specified period of time.
I wonder in what circumstances you could get such a stand-alone Russian visa, and at what consulates?