About The HTA
It’s lining and it should be about 2 1/2” wide
Do you prefer to using lining instead of a cotton tape for the roll line because lining can't possibly bite into the cloth, creating a ridge?
That’s one good reason.
The other is that the lining bridle is used at the neck when join to the collar to cover the cloth and canvas which gives it a nice neath finish at both fitting and finish garment.