Subdividing and keeping sharp edges

Is there possibly a way to subdivide services but keep the edges sharp I’ve googled like crazy and can’t find anything I have a model of the helmet I made I want certain ages to stay sharp but round out the rest of it

Artisan tools.

It kinda comes down to how you are subdividing for a specific answer.
But both Artisan and SUbD have a crease tool.

I tried artisan tool but it doesn’t actually change the mash in sketch up it looks smoother but when I imported to my 3-D printing software it’s exactly the same