in nightfall do you have to find (or buy from other players) all insignias to make the armor type you want, or armors with insignias are available too?
is there any insignia trader there?
Insignia
Reza
Pkest
rune traders have insignias (when they are in stock) and I think all the Elonian armor needs insignias. I think all insignias should be sold by armorers so you can make whatever armor you want.
cosyfiep
if you have access to a priest of balthazar you can look at them all (cant buy them, but you can see what there is).....then you can try to find the ones you want later.
HawkofStorms
They also drop on armor pieces just like runes (though they seem more common once you get on the mainland).