3M Super 77 spray adhesive, if you can get the label off intact.

I have had some limited success in removing labels with a heat gun to soften the old adhesive. Some foil substrates will peel off but the old ink may crackle badly. Others will simply tear, so be aware that you may have to heat and pull, heat and pull, repeatedly. It can be laborious and frustrating. Small labels are much easier than large ones, btw.

With my Follis seat tube, I removed the art, but it tore in several places. I saved every scrap, sticking the pieces to a piece of archival white paper and reassembling it like a puzzle. Then I generated a high resolution scan of the flat decal and used that to recreate the original artwork. Thus, I wind up with the original sticker on a flat card, a digital scan that was necessarily touched up in Photoshop where the tears are located, and ultimately an Adobe Illustrator vector file from which I created a new water slide decal.

And yeah, what a PIA!