Please take your quilt out of the plastic bag and store it in a old pillow case, or on a quest bed and keep it covered with other quilts or bedspread or a cedar chest the idea is to keep it from the light so it does not fade. If you have quilts folded and stored it's a good idea to refold them every three or four months. Quilts need to be able to breath. I have worked with many appraisers and storing quilts is always a topic they cover.
Just thought I would pass it on.
Thanks