I usually buy regular pop corn, the old fashioned kind and then put it in a place pan I bought years ago that has an insert that is wonderful for popcorn. Is really the steamer container. Just push popcorn setting on the microwave.
One day I was experimenting as the pan I wanted was in the dish washer. So, I just the same amount of popcorn and put it in a paper sack and popped as usual. It was great that way too.