A Punjabi turban is a single length of cloth, usually five to seven metres, sometimes more, wound fresh each time. There is no fixed form and the style says where a man is from and what he belongs to.
The Patiala shahi pagg is broad and layered with a fan at the front, associated with the princely states. The Majha style is narrower and more angular. The Malwa style differs again. The Nihang dumalla is round and tall and wound with a chakar, and the farla is a length left hanging.
The Pothohari style, and the styles of the western districts, largely left Indian Punjab in 1947.
Tying one properly takes practice and several minutes and is done fresh daily. A tied turban that is taken off and put back on is a patka or a ready-made, and it is not the same thing.
The colour carries meaning by context and not by rule: blue for Nihangs, saffron at political gatherings, white for elders and for mourning in some families, and everything else for everything else.
A young Punjabi man learning to tie one is being taught by someone, usually his father, in front of a mirror, and that transmission is thinning in the diaspora faster than any other practice.
It is tied over an under turban, a keski or a fifty, with the hair knotted in a joora on the crown. What is being wrapped is not a bare head, and where the joora sits and how big it is accounts for a good part of why one region's turban has a different shape from another's.
Nobody sells turban cloth as a garment. It is bought by the metre, voile or malmal, torn to length, washed, starched, dried stretched between two people and folded into a pooni before it can be tied at all. The preparation takes longer than the tying does.
The turban is not a kakar and it is the visible thing, which is why almost every legal and social confrontation about Sikh identity abroad has been about it rather than about anything in the rehat.