Ken, you will want to use plastic knives, not forks. Then you can write on the knife blade.
I have heard of people putting the clear Scotch tape over the sharpie on the knife blade to add extra life to the writing while buried.
I haven't had any fade.... but I have drastically reduced the number of plantsI have so it's not much of an issue here now and I no longer use knives, maps are good enough.
