Apple has released over half a dozen printer and scanner driver updates for Mac OS X 10.6 Snow Leopard users. These updates are focused primarily on brands that cater to business and enterprise users.
Included in this round of update are drivers for printers from vendors like Brother, Infotec, Lanier, Gestetner, Ricoh, Savin, and NRG. The updates range in sizes from about 20MB to 105MB.
You can download these updates from the linked pages above at Apple’s site, but any relevant updates for your Mac(s) should also appear in Software Update.