The regular CD's (the slightly green tinted ones) are one layer of plastic and just a coating on the bottom. When you cut a butterfly out of one of those, the backing could peel off, for one, but what you cut is what you get. There won't be any change. They are great for making all kinds of neat things and for also peeling off the backing and adding your own Designer Series Paper.
But when you cut a BluRay disc, they are constructed of two pieces of plastic with the coating between the layers. What happens when you cut it is amazing: The two layers will come apart and on one side, you'll have most of the coating with this cool watermarked BLUE metallic layer and on the other layer, the coating will be purple watermarked and the butterfly will be mostly clear! Give it a try! Don't mind the creaking and cracking as you run the discs through the Big Shot... I scared a BUNCH of guests at my last class!
Paper and Ink:
Baja Breeze and Pacific Point Stampin' Pads
Baja Breeze, Pacific Point and Whisper White cardstock
Scallop Trim Border Punch
Big Beautiful Butterlfies Sizzix Die