And suddenly I see them everywhere. So I made this post, mainly for my friend Patrik/Sir Franz, who makes awesome early 16th century Swiss clothes. And who may, or may not, wear this kind of underwear under them - I wouldn't know. I guess that I could ask his wife.
There are enough images for us to know how they were constructed: with a tie in one side, making them ideal for stripping I guess.
Anonymous woodcut used for Hanns Sach's play: The evil smoke
These pants are black, which you also see in some paintings from the period.
Israhel van Meckenem: Battle for the pants - said pants lying on the floor.
Erhard Schön: There is no greater treasure here on earth than an obedient wife who covets honour
The woman with the whip has the underpants of her husband hanging on her arm.
Albrecht Dürer's The men's bath
And, since a few years, we have, as you probably already know also an extant example of this kind of male underwear, found in Schloss Lengberg in Austria.
It really matches the images perfectly.
Since I have made just one 16th century outfit for my husband and that one is later than this period, with puffy pnats that don't require such minimal underwear, I am not sure if he really needs a pair of these. I am actually certain that he doesn't. But my friend who make Landsknecht costumes probably do.