The Glassblowing book is a book that players can obtain from the reception at the Observatory north of Castle Wars, in the house west of the Furnace on Entrana, or from a bookcase in a player-owned house, but only after it has already been picked up once before. It explains in depth the art of blowing molten glass, which is a part of the Crafting skill.
Details about glassblowing may be found here.
Ultimate Guide to Glassblowing
Author: Fritz the Glassblower
I can tell you now, the art of creating glass has long been a valued trade in RuneScape. Not many could get by without the use of some item made from this marvelous substance.
It's within this book that we cover the basics of the art, in a hope to get you hooked on this popular pass-time and trade. To start with, you will need a few essential items:
An empty bucket.
These can be purchased from the majority of general stores and are required to carry the sand you will need to make glass.
A glassblowing pipe
Found on Entrana or often just north-west of the Ranging Guild. As it's name suggests, this is used to blow air into molten glass.
Seaweed can be found on the shore in many places, but it is also a frequent find when Fishing with nets. This you will need to create soda ash - an important ingredient to the process.
Made by burning seaweed, you will need this to make glass. Other than making it yourself, you can purchase from other budding glassblowers.
With these items you are ready to begin! You'll need to find a sandpit and there are a few dotted around RuneScape. Try the isle of Entrana or Yanille, for example. Use your bucket on the sandpit to fill it up.
Next, you need to find your way to a furnace. Turn your seaweed into soda ash by using it on a range before using a bucket of sand or soda ash on the furnace to create molten glass.
The last stage is simply to use the molten glass with your glassblowing pipe and, depending on your level of skill, you can create a variety of items.
I hope you enjoyed this guide, and please keep an eye out for more of my titles!