Question

is All fingerprints are invisible to the naked eye.

Answer 1

No, you can see the fingerprints on your fingers cant you?

Answer 2

yes

Answer 3

and you can somtimes see fingerprints that were left on glass

Answer 4

I agree, but on some other surfaces like some woods, some plastics, metals, and concrete you will not see it, or not as well as you would on some glass. On the most part they are considered to be invisible to the naked eye.