I have made this fondant twice and each time I've made it, it ends up not having a good stretch in it, the slightest pull and it looks grainy (that's the best word I can think of to describe it). When I'm making it, I add in less than the 3 1/2 lbs of powdered sugar, I probably put in about 3 lbs. The recipe just says to knead until smooth, what is smooth exactly and what is the texture supposed to be like after it has rested. I've worked with satin ice and wilton, but I've never been able to get any homemade fondant to be the same exact texture as store bought fondant. I always think I have it perfect when I'm making it, but after it has sat, the texture just isn't right.