In another question I figured out how to get some basic info on my poorly labelled trailer tires.
Now that I know the inflation pressure, load rating, etc., I'd like to write this on the tire in some way, ideally permanently. I don't want to go from memory long after when I need to check the pressure (nor avoid doing it because I'm unsure of the right values).
Is there any way to safety and effectively write (or paint?) on a tire?
There's nothing you can do to reliably and safely mark the tires because it's such a harsh environment. They're being spun hundreds or thousands of times per minute, blasted by wind constantly and exposed to heat, cold, dirt, salt (in some places), rain, ice, and sun. A sharpie just isn't going to last, and any sticker will go sooner or later no matter how well they are glued on. This is the reason tires are marked by raised material or impressions in the material - it's the only way they'll last.
Cutting into the material of the sidewall is an option, but not a good one as you could weaken the tire and cause a blowout, your best bet is to put the information someplace it can be referred to on the trailer or the car, someplace protected from the elements.
