Just wondering.  I've done a few and never cut or wounded any limb.  I have many air layers looming.  I owe people.

My last ones worked, but I'm thinking of this new way I saw on you tube.  Dude uses no plastic, but he does wound the tree.

Tomorrow is the day I have to start many.

Give me your best stuff!

Suzi

I dont. I just take a limb strip all leaves off. make sure a good many nodes are under soil i use those tall narrow pots 12 ×3×3. Slide pot over limb. ( no leaves so this can be done. Water it like a pot. Very successful and fast root development. Way easier then the water bottle. I can do one in less then five minutes

No need to cut the bark at all
Make sure you use something that is easily accessible for regular watering.
The key to a successful air layer is to compact the soil firmly against the limb and water often.
And make sure it's secure so it doesn't move on windy days.

Figs will usually root without it, but many other air-layerable plants will not develop roots without the girdling.

I have done it both ways, my success rate is better when I scrape the area or cut it.

No, you don't have to. BUT in my experience you get better results if you do.
BUT (another one, I know,,)  I do not girdle,  I take an old fork and scratch lengthwise, covering the area to be rooted.