I cot some spare pieces out and took some pics with a metal mechanical ruler on them. This first one shows a Moda jelly roll strip measured from side to side. You can see that the left zero mark is on the peak of the pinking while the right 2.5" mark ends up in the valley of the pinking. The peak on the right side comes out at about 1/16" more, so is like 2 and 9/16".
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http://i1018.photobucket.com/albums/.../Pinked_01.jpg[/IMG]
Here's a charm sqaure that comes out at 5 and 1/16":
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http://i1018.photobucket.com/albums/.../Pinked_02.jpg[/IMG]
And a layer cake square that comes out at 10 and 1/16":
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http://i1018.photobucket.com/albums/.../Pinked_03.jpg[/IMG]
If you're mixing pre-cut pieces like this with yardage cuts then it can cause things to be off if you're assuming the pre-cuts are exactly what they should be. I've even gone so far as to cut the pinking off 2 sides of charm and layer squares to get them to a true sizing. But that's a pain when you have to do it on 40 pieces.