Un-Blackened Brass Badges - Questions

[CAM]

These may be a strange questions.

I am aware of the reasons for blackened brass badges and also aware that they were either factory blackened or painted and then some had parts ‘highlighted’.

I have seen several badges that have been previously blackened but are now almost entirely back to brass – including the back.

Any painted badge would be easy to ‘strip’ but the factory blackened would take a lot of effort.

My questions are:

1. Why?
2. As the badges seem not to be worn down with polishing, how?