[rayiner]

> It always surprised me that this was not true in air and airplane wings were supposedly best when glossy.

I was an AE major and I don’t recall ever learning that airplane wings were best when perfectly smooth, even as a simplification in undergraduate courses. We were taught that drag is reduced by maintaining an attached laminar flow.

Airplane wings are glossy because they’re metal (or CFRP) and painted for durability and corrosion and UV resistance.