Tailors can make 8-20 slot Craftsman's Bags (New crafting materials are placed here first when looting).All three professions can make invisible bags (which don't show up when selling to merchants).20 slot bags can be made at max level, and they require a superior rune of holding (10 gold) to make.In addition to raw materials, these higher level bags require an increasingly expensive vendor item called runes of holding. Each tier of crafting makes a higher quality bag (10 slots, 12 slots, 14 slots, etc).8 slot bags can be made by crafters (tailor, leatherworker, armorsmith) with 20 tier 1 materials (jute scrap, rawhide scraps, copper ore).
4 slot bags can be purchased from vendors for 32 copper.You can have 250 of each crafting item stored. Crafting Material / Cooking Material / Mini-Pet Storage.Here are some things I've found out about GW 2 to help me plan my storage space. The main problem is that I love to craft and quest and always have a ton of those items on hand. I always run out of inventory space in any MMO I play. Guildwars 2 Inventory And You! - A Guide To Maximizing Inventory In GW2