Buy RS3 Masterwork white cloth
Masterwork white cloth is a members-only item in RuneScape 3. It is a bright, glowing cloth used to craft masterwork magic armour and the masterwork ranged cape. It is also used for repairs. One cloth fully repairs one piece of partially degraded masterwork magic armour.
Making this cloth yourself takes a lot of work. You need level 110 Crafting and the achievement "It Should Have Been Called Ancestral". Each cloth also costs 10 Croesus flakes and 50 Starbloom cloth. Crafting one cloth at a loom takes 5 minutes and gives 1,250 Crafting experience. A full set of masterwork magic armour needs 20 cloths, which takes 1 hour and 40 minutes of crafting time.
Buying the cloth lets you skip the grind. You get the finished item without gathering flakes and Starbloom cloth or standing at a loom.
The item is tradeable and noteable, but it does not stack. It weighs 1 kg and is always kept on death. It cannot be disassembled or alchemised. Its examine text reads: "A powerfully luminescent cloth used to craft masterwork magic armour."