there are lots of very nice batts on the market- unfortunately not available at walmart. always read the package- it will tell you the % of shrinkage you can expect. I love all of the batts from the dream company---dream green, dream wool (my favorite all time) dream poly, dream cotton, dream orient, dream bamboo....there are more too- all great batts (and yes- i've tried them all)
i also really like the Hobbs batts- 80/20, heirloom black, cotton & poly batts from the hobbs company (many available & on sale often at "Connecting Threads) personally i Never use warm & natual (unless a customer brings it in-wants it in their quilt) the dream wool and the Hobbs wool batts do not shrink...most of the poly batts do not shrink. cotton batts shrink any where from3% up to about 10%...always read the packaging which will tell you how much shrinkage to expect, how close you need to quilt, and how it should be cared for/laundered.