Trader's Backpack is a backpack that allows for carrying of large quantities of trade goods and building materials due to its allowance of stacking items. Can be purchased from any General Item Trader. Stackable bonus minimum and mult are both 3 resulting in the ability to stack items up to 9x their normal amount.
The built-in sun shader provides no benefits and is purely cosmetic. The Trader's Wooden Backpack has slightly larger penalties, so it is an inferior version to the Wooden Backpack.