What's the usage model of VG_BW_1 color format?

I’m figuring out what’s the typical usage case for VG_BW_1 foramt?
I think the grayscale graphics can replace it. It seems that the
black/white graphics can only save memroy size, right?


Right. It’s all about memory saving on the client side.

A typical use-case for the BW_1 format would be a fax viewer application.