Find the make, MODEL of the printer and then check the printer's specifications. That has been the safest course but keep in mind that as the printer ages it may lose the ability to print on it's heaviest specified stock.
Bob
Does anyone know what is typically the safest weight of cardstock you can use on an Epson printer to print simple greeting cards? Thanks.

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic