The same Super Negin threads, graded to ISO 3632 Category I before milling, then milled fine with nothing added — no colour, no filler, no carrier.
Powder does one thing threads cannot: it disperses the moment it meets liquid, so the colour and the aroma go through the whole dish instead of sitting in a few strands. That is what you want in rice, in dough, in a drink, in anything that should be even. Threads suit the dishes where the saffron should be seen.
Neither is the better grade. They are the same saffron, cut for different jobs.
