I packed images into atlas to use it in unity, and I unpacked it because I needed to modify it in spine again. However, it seems like the transparency setting is gone, and all transparent parts and outlines look grayish now. The transparency works fine as image atlas in unity, but since spine doesn't seem to read atlas files so I have to unpack it to see it in spine. So I would like to know how to unpack image atlas without damaging image transparencies.

I was searching for alpha setting, and found out it is in 3.8. I use 3.7 so I didn't know the existence of it. Anyway, now I can unpack the atlas without problem. Thank you very much!