Try a profile for a different material that is similar such as Oracal 3640.
Best thing to do if you have the full pro version of flexi is to buy an i1 ( the i1 is all you need you dont need any software as flexi has everything you need to build profiles built in) and make your own profiles it takes a little bit to make really good profiles but once you learn how you will be glad you did and you will have the best prints you have ever had.