Glassblowing in Ultima Online is a special skill, in that it doesn't have skill points. It's just you can or you can't do it. The skill can only be learned after getting 100 points in Alchemy. To learn it, the book "Crafting Glass with Glassblowing" has to be bought for 10.000 gold in Ver Lor Reg on Ilshenar. Once read, the book is destroyed and the skill learned.
To use it, the player needs sand, a blowpipe and be near a forge. Besides simple potion bottles (which make potion brewing in Alchemy much easier), the skill is mostly used for decorative items. However, there are some pretty strong magical items, that need this skill in their creation.