My grandpa built a lake cabin in the late 1940s. He poured a concrete sidewalk and between that and the cabin he poured a small slab where he put his footprint and wrote his initials and the date. The cabin was sold about 25 years ago (long, sad story). Last summer, my sister and her husband went fishing on that lake and stopped in to see the old family cabin. They talked to the owner for a while and then remembered the footprint. It was still there but for some reason, it was upside down and halfway under the cabin. The owner didn’t even realize it was there - never noticed it. He told them they could have it. It has now come into my possession. I have it in my garden. After 70+ years, the concrete has become worn by weather, etc. His initials are still visible and the footprint is starting to fade away. The date is completely gone.
Is there any way to preserve what’s left? Is there some way to make what’s left more visible?
If you want to truly preserve it, don’t leave it outside. Put it in a climate controlled environment, etc. Think of a museum type environment.
Otherwise, take some photos of it, to save the memory. And not worry about it fading away.
I think the easiest thing to do would be to encase it in resin. I’m sure there are ones designed for outdoors that won’t get discolored or translucent from the elements and those two part epoxy/resins are very easy to work with.
You could make a mold of it and have a negative made out of rubber or metal, then you could get some concrete, use the negative to make copies to put outside in your garden, and then preserve the original in resin like Joey P suggested.
This sounds like the best approach for the long term. It’s fortunate that it’s been preserved this long. Polyester resin is also easy to use but I’ve found will darken over time, I think due to exposure to light, but not sure about that. Totally encased the slab will probably last outdoors for a very long time as well.