I think most people use labels from Toyhax (formerly Reprolabels):
https://toyhax.com/
They sell a variety of different stickers, silver back, clear back, etc. Here is an example of their decepticon stickers with a clear back. You see that they come in a pack with multiple sizes so you can decide what size fits best for the figure.
https://toyhax.com/symbols-for-tf/48...ar-backed.html