You use the dream cloth to make the big bags, which are not BoP. This basically ensures that the tailor is forced to farm his own mats to make those bags.

However - it ensures that you don't have a fractured mat market. You wouldn't have the mats to make the cloth salable as well as the cloth both on the AH; just the mats. It also puts a limit on how fast any item made with the cloth can be produced since you can't trade the cloth. That way you couldn't have, say, 5 people all use their CDs one day and trade all the cloth to one person who makes an item with it. If the cloth is soulbound, you can only use the cloth you yourself create.

However - it ensures that you don't have a fractured mat market. You wouldn't have the mats to make the cloth salable as well as the cloth both on the AH; just the mats. It also puts a limit on how fast any item made with the cloth can be produced since you can't trade the cloth. That way you couldn't have, say, 5 people all use their CDs one day and trade all the cloth to one person who makes an item with it. If the cloth is soulbound, you can only use the cloth you yourself create.

However - it ensures that you don't have a fractured mat market. You wouldn't have the mats to make the cloth salable as well as the cloth both on the AH; just the mats. It also puts a limit on how fast any item made with the cloth can be produced since you can't trade the cloth. That way you couldn't have, say, 5 people all use their CDs one day and trade all the cloth to one person who makes an item with it. If the cloth is soulbound, you can only use the cloth you yourself create.