tough question........ mainstream usually means common and well known.
If youre talking cards with an ACC# (American Card Catalog Number), there is only one answer ....the 1922 T231 Fan Cigarettes.
There are only 2 examples known.... a Frank Baker (Hi Leon
), and a Carson Bigbee thats been seen as a zerox copy about 30 years ago and never since (as far as I know)