At the time of the French Revolution, most of the lower classes wore knitted garments that could be home-made.
The culottes were made from woven fabric by tailors, and so were expensive. So it was easy to tell the rich from the poor.
Incidentally, I suggest not pronouncing the second "s" in sansculottes. It takes an extra effort, and sounds horrid.I refrain from saying ignorant.

I just remembered Shakespear using "sans". I expect he did
pronounce the final "s". But he could do no wrong.

All the World's a Stage....

The sixth age shifts
Into the lean and slippered pantaloon,
With spectacles on nose and pouch on side;
His youthful hose, well saved, a world too wide
For his shrunk shank, and his big manly voice,
Turning again toward childish treble, pipes
And whistles in his sound. Last scene of all,
That ends this strange eventful history,
Is second childishness and mere oblivion,
Sans teeth, sans eyes, sans taste, sans everything