Here is an alternatives that does the same thing: https://www.amazon.com/Ear-Tag-Marking-Pen-Black/dp/B000HHM5GI
They all have “fading” and “fades” comments.
Then there’s the paint marker alternative in many colors: https://www.amazon.com/Forney-70822-Marker-Paint-Yellow/dp/B000TGC3VO
This last one is the ubiquitous marker for industry for pipe and plastic, but you must follow directions or you will end up with color all over the place! 