I didn't even know these existed but came across an article talking about plastic razor blades being ideal for removing labels, pin stripes off automobiles, etc. without damaging the surface underneath. Found a dealer on Amazon who offered a package deal of 25 blades with a comfortable plastic scraper handle with another blade already installed for under $9 with minimal shipping. Turns out it works really great! And using Goo Gone for any residual glue then cleaning up with a Windex wipe works perfect with very little work. I keep a paper towel with the Goo Gone on it in a zip-lock bag and my current Windex wipe in another zip lock for quick access whenever needed.

Here's a link to the manufacturer's page showing the kit that I got through Amazon.
https://miniscraper.com/product/titan-scraper-rugged-yellow-and-black-holds-metal-and-plastic-blades-comes-with-25-safe-scrape-plastic-double-edged-blades/

By the way, no matter what type of labels you put on plastic cards, including something like the Avery removable labels, they will damage a card over time once the glue and/or label dry out. While going through this latest slot card collection I acquired I've come across a number of cards that were severely damaged by labels, especially if the clear plastic lamination is loose.