Butane is made by many companies as well as purities.
We have heard that the best butane comes from Europe, but this could be just a feeling.
We have also talked with butane manufacturers and they say we can have any purity on the label but it is all the same. Many brands do 7x refined, 10x refined or whatnot. This is just a gimick and not true.
We do believe that Europe is held to a higher standard then China or India.
Use the butane recommended by the torch manufacturer.