Hi Cindy. I'm Cindy too. I use space bags for seasonal clothes and blankets. Fill a bag and then attach it to your vacuum. The vacuum will suck any air out. The bag ends up flat . I stand them up in my closet. (You don't have to stand them up, that's just the way I do it.) They will also fit under a bed. I think your shirts could be stacked in a space bag while being stored. Good luck Cindy.
Do you want to store the shirts for long term, such as on a seasonal basis, or do you need frequent access to them as well?
Cindy....If you are packing away for season I would use plastic totes and label.
I use Space Saver bags for storage. The original S/S bags come with a small hand unit to extract the air if you don't want to pull out your vacuum and/or are traveling. I take the hand unit (small & light weight) with me. Saves space in luggage. I store packed items standing up. I get more bags in a space standing up rather then laying flat. Good luck, Ilene