I use resin supplied by purefreedom, found it to be the cheapest and the best one so far. I would recommend that when you purchase it, if can, go for a complete bag. As supposed to buying small quantities, as you want to make sure its fresh and not drawing moisture from the air. (So if the supplier hasnt a huge turnover of supplying resin, you dont kno how long the resin has been subjected to open air before they send you a 5l bag thats tie griped fastened. Hence it will not trully last. Whereas a full 25l bag, your in control.