Looking for a bit of a white whale.
It was a short panty tf comic, where a girl (apparently a princess) was turned into boring plain white panties and derided for this by the girl who transformed her.
I think there's a second part where the panties are used as a cumrag to jack off a muscular futa(?), and then thrown on the ground and stomped by the girl who transformed her.
IIRC the comic was monochrome, and I think the artist also did a lot of giantess stuff?
I haven't seen it in like years and haven't been able to find it.

I'll try and post some from my collection in advance