what is the difference between satinice and pettinice?

It is a preference really. Some decorators swear by pettinice and some by satin ice. You should probably try both if you will use enough of it and see how you like each one. Different climates can make a huge difference in the way a product handles. I have SI right now but it's a bit soft for my humidity so I'm going to try the other when I get some. I have some of Geraldine Randlesome's ML sugarpaste to try. She swears by it. Now you know less than you did before you asked.

I have used both with much satisfaction. Pettinice seems a little firmer and more prone to cracking than Satin Ice. However, it very hot and humid kitchens you may find it works better. Satin Ice is still my favorite. Alan