Used with Glassblowing to create items made of glass. Can only be purchased from the Gargoyle Alchemist Vendor in the Royal City of Ter-Mur.
Interestingly enough, the blow pipe displays properties for use as a weapon, but cannot be equipped. The properties vary for each blow pipe.
To use the blow pipe, make sure it is in your pack. Double click and the Glassblowing menu will appear. You also need Sand in your pack, and need to be standing near a Forge to actually create anything.