The tools include a blowpipe, a small marver, blocks, and tweezers. You need a source of heat to work glass.
Your knowledge of glassmaking techniques aids you when you examine glass objects, such as potion bottles or glass items found in a treasure hoard. For instance, you can study how a glass potion bottle has been changed by its contents to help determine a potion's effects. (A potion might leave behind a residue, deform the glass, or stain it.)
When you study an area, your knowledge can aid you if the clues include broken glass or glass objects.
With 1 minute of study, you can identify the weak points in a glass object. Any damage dealt to the object by striking a weak spot is doubled.