if you buy kona at joann it is a different and lesser quality. if you hold it up and compare it to kona sold at a real lqs, you can immediately see the difference. it is much thinner. if you want a decent white go to a private lqs.
sometimes a reputable fabric company will manufacture down (that is, lower their standards) in order to meet a lower price point for a chain of stores. the fabric store, in this case, JA, gets the 'name brand', kona gets the huge contract to supply the JA stores and we get stuck with very slightly less than kona prices and yucky JA quality.