It seems that my quilts with ‘cotton’ batting have more prominent creases from being folded, than my other quilts:

See my “quilt care” section for ideas, but in a nutshell, refold your quilts often so the crease does not have time to ‘set’. If possible, store quilts rolled up over a cotton covered tube, or lay on a spare bed. You can layer many quilts on the bed, and cover with muslin to protect from dust and light – rotating the top one would also be a good idea!