You can normally test for in-ies and out-ies on surfaces with the tip of a fingernail.
It either comes to a halt on something raised, or dips a little into something more intaglio.

The tip of a fingernail is also good for testing for age-related wear that cannot be seen on a tiny base ring.
(By "tiny base ring", I mean the actual bit of the base that makes contact with a surface. It doesn't always
all make contact.)