I am doing a presentation on different mouthpieces and how to choose them in my studio class. I was wondering what the difference is between gold or silver plating on mouthpieces and what they do to the tone and ease of playing, if they do make a difference.
Thanks!

The gold plating makes the mouthpiece feel smoother - and easier for embouchure adjustments. You can also get acetate rims (see http://www.horncups.com) which are hypoallergenic or kelly mouthpieces which many serious horn players would frown on without even trying them!