However after a while it became annoying to try to peel the small stickers off the backing, then fumble to center a small sticky thing over the offending LED.
so... I use painters tape. I started with the blue kind, but switched to black. Easy to tear or cut, easy to size. electrical tape isn't sticky enough.
I choose an appropriate number of layers for the problem.
Most lights just need one layer. Sometimes I need to kill the LED directionality to be acceptable. And some indicator lights need to be dim, not off. Think an HDMI switcher where you need to know which port is active, or router port activity lights.
Sometimes I put a second layer when I need less or no light.
I couldn't tell if he was serious, kidding, terrible or a genius.
...and your comment asks me those questions too! lol :)
Are you hoping to just make some money from strangers? You cannot get much commission from the $1.50 item, so I am imagining you hope someone clicks on your link and then buys unrelated expensive item.. This feels really sleazy, does this bring you any actual money?
I used the ultra-dim for the (white) temp display on my Dyson fan in my bedroom, and the blackout for the brighter-than-the-sun blue LED on my charger brick. Also used the dim one on a smoke detector because my 5-year-old thought it was watching her or something.
They're absolutely great, and you can even keep a couple in your suitcase and fix horrible lights in hotel rooms or AirBNBs if you're so inclined.