A well made English detachable evening collar, of traditional design.
I am not sure of the exact date it was made, but probably around the 1930s to 1950s.
Maker's name illegible - it looks like the sort of "registered user" stamp used by the Trubenised Users' Association.
White cotton Marcella (the textured cotton also known as "pique" or "golf-ball texture").
It can be starched if preferred, but this is not strictly necessary.
Note: you will need a pair of collar studs to attach the collar to your tunic shirt.