Found this interesting article at WWBW (which is a great place to get stuff BTW) by Greg Vail.
“With that said, let’s start with the most common finish – lacquer. Lacquer is a liquid substance that dries hard, protecting the metal of the sax and maintaining its beautiful appearance. Most saxophones are made primarily of brass, and then lacquered. There are saxophones available that do not have lacquer on them known as un-lacquered instruments. The difference between the same model with and without lacquer can be significant.”
Check it out.