Why do you want to make it? It will only be 'ready roll' if you roll it out. I've made it twice. The first recipe I used was so sticky I couldn't do anything with it. The second felt lovely until the next day when it was as hard as rock. If the 'ready roll' isn't the size you want just buy sugarpaste and roll it out to the desired size. There are several brands on the market, some of which are available from supermarkets and others from sugarcraft outlets.
If you need some guidance as to how much you will need for a certain size let me know.