Is this a stained glass window...

Source:  Is this a stained glass window...    Tag:  lead glass

... or a "stain-glassed" window? I've always used the term in the title, but I ran across the alternative in a book today.

I'm comfortable with a window being called "glassed," but since the material depicted is (as far as I know) "stained glass" rather than "stain glass," I would think the logical term would be "stained glass."

Google does yield thousands of hits for "stain-glassed," but I would think it must be a miscontrual - unless some reader knows differently.