I tend to save everything related to my cake purchases, including the product sheets that come in pans (yes even the round ones) with the information on the back. One thing that I've noticed is that the amount of batter that they state on these sheets is different from the Wilton guide for batter even though it's a Wilton pan. Has anyone else noticed this?
I had to check when I saw your post because I knew I still had some pan inserts. I have the inserts to the 10 x 2 and 14 x 2 Wilton Performance Series pans. They state, respectively, 6 cups and 10 cups. This matches what is in the current (2012) Wilton yearbook. I wonder if the chart in the yearbook has been updated...or could it be due to different styles of pans?
If it's a very old pan (and printed insert), they did update the serving guide to fewer servings years ago.
I was looking at a page that I downloaded from their website. The inserts are only about a year old at the most. I will have to see if the list that I have is different from the one in the new yearbook.