If the outer wrapper is gone, the bulbs were likely harvested too late. Each green leaf on the garlic plant extends underground and is also a wrapper around the cloves. As the green leaves die off, so do the layers of wrapper. If you allow all of the green leaves to go brown your wrapper will be gone.

Garlic should be dug when there are still 3-5 mostly green leaves. Your wrapperless bulbs are still good for eating, but will not store as long so you should use them first.

TomNJ

And I thought I was harvesting too early! Most of the leaves are still green (I usually harvest when about 40% of the leaves are brown, and most aren't there yet). So I suppose I should just harvest the whole crop?

What happens if you harvest too early?

If most of the leaves are still green, then there must be some other factor at play here - don't know what. There are no consequences in harvesting at this stage.

TomNJ

I have had garlic hanging in mesh bags in my garage for a
long time. They are starting to sprout. The outer wrapper
are real loose and the bulb feels dry. I would like to
plant them back out. Do I need to take the loose wrapper
off first?
Thanks

You need to separate the cloves and plant them individually. You do not need to remove clove skins, only the outermost wrappers that holds the cloves together, and then only enough to separate and remove the cloves.

TomNJ