A tassel on a dining chair is a lovely detail and a maintenance problem, because a tassel is the one thing on the chair that will genuinely need cleaning or replacing within its life. It hangs at the height of a passing sleeve, it collects dust in a way a flat surface does not, and its threads are the softest material on the whole piece.
Sewn permanently into the seam, it becomes something you cannot clean properly and cannot replace at all without an upholsterer opening the chair.
So ours are not sewn in. A small loop is stitched into the corner of the upholstery during covering, and the tassel hangs from a concealed hook that engages that loop. It is invisible in place, it does not move under normal use, and it lifts off between two fingers.
That means a tassel can be taken off before a set is cleaned, replaced if it wears, or removed entirely if you decide in three years that you prefer the chairs without them - which some clients do, and it is their chair.
We supply a spare pair with the set, because the one that gets caught on something is never the one you kept the receipt for.