I've never cared for a woman with any amount of makeup when, IMO, she looked better without it!
I've had the luck/opportunity to be with a couple of Kgirls without makeup.
I always asked after the first time I saw them if I could wash their face in the hello shower, even though I knew the answer would be No, are you crazy! It's usually, an early session.
Had better luck on the last appointments, but not always.
On one 2 hour before start time appointment, I was waiting for the green light.
When it came it was 12 or so minuets past the early start time, the Booker said, because the girl was running a little late.
When the door opened the girl acted kind of shy, hid her face in my chest and hugged me!
I totally didn't recognize the girl and thought her roommate had answered the door for her, because of lateness!
It took a few minuets to catch on that it was the girl I was there to see, fucking funny!
IDK about plain, I see it as a cleaner/cuter look, but it's all subjective anyway!
IMO, some guys want that super sexy wicked vixen look.
Another look is the no makeup innocent untouched style.
Then you have a few in between those two looks.
But what we usually get is the look that the Kgirl figures is her best look and best make up job!
Just my opinion and experience.