After they were phased out of the warriors' arsenal, they were then used by the scouts as a suport/skirmish weapon. Slings were notably used by the scouts to help turn the tide of the Vei'Visa Battle by distracting the Siksa'Santi warrior who was deflecting the Tei'kaliath arrows.
Eventually the scouts replaced their slings with Golem Crossbows and the Tei'kaliath's first projectile weapon was phased out of service entirely.
In order to make a sling, a small yet unknown ammount of cloth was needed. Said cloth was usually donated from any spare clothing the Tei'kaliath had on them, thus technically slings are made out of Phantom Items. However it should be noted that while slings were made of phantom items, they themselves were not phantom items and were listed under the clan inventory on the front page like any other resource.