Here are some things I was very lucky to 'acquire' during my recent shift at Antiques on High - They are vintage, from the 1970's, collars and cuffs which have been hand embroidered with proper mirrors by craft workers in India (or thereabouts).
The collars and cuffs are embrodered onto thin cotton, within printed pattern lines as you can see on the detail picture above. I am supposing that you cut them out with a seam allowance all the way around, and then sew them on, with seam allowance tucked under, to your chosen garment, which I think should also be white as with the best will in the world, it would be hard to entirely hide the white fabric which holds them.
Aren't they exquisite? This green one is my favourite. Here is a detail of the back. The thread used is a thick woolen type of thread - or should I say thin woolen thread?. What I mean is that it is thicker than the usual embroidery floss, but thin like darning wool. All of them have a yellow and black chevron design incorporated, I wonder if this has a special meaning?
I guess those who like to embroider, could make these quite easily to their own design, to sell, or perhaps even for gifting to crafty friends or family members.
These lovely panels need to be cleaned. Very very carefully, by hand, in cold water and on a sunny day!