from my Stack of Teapot Books
What is Crazing?
Crazing is the spider web looking cracking on the surface of your teapot. It can be thin, fine lines in the surface only; or it can be firmer, brownish lines that have penetrated the glaze completely. Crazing can appear anywhere on both the inside and the outside of your teapot - even the lid.
What causes Crazing?
Crazing can be caused by a problem glaze. However, it is most often caused by putting boiling water into a cold teapot.
How can I prevent Crazing?
If you have a brand new teapot OR a teapot that doesn't have Crazing and you'd like to keep it that way: The best way to prevent Crazing is to always warm your teapot before brewing. Use hot NOT boiling water. Once the pot is warm, empty the water and then add your tea and boiling water.
Can I repair Crazing?
The easy answer is NO. There is the Old Wives Tale to "boil your teapot in milk" method. But do you really want to use that much milk? If you love your teapot use it the way it is.
Is it dangerous to drink from a teapot with Crazing?
I have found mixed answers for this question. If the teapot is crazed on the outside only - the answer is NO. As for crazing on the inside: Some say it's okay, others say not-okay. My opinion is this: If there are deep crazing marks on the inside...enjoy the teapot by putting it on the shelf and admiring it. Perhaps there isn't a problem in using it. However, this may be a perfect opportunity to purchase another teapot.
As you can see from the photos below, there is hairline crazing on the surface and bottom of the teapot. HOWEVER, there is no crazing on the inside. YES, I would use this teapot to the fullest, remembering to warm the teapot first before brewing my tea.
This charming teapot has a log cabin motif. It has miniscule crazing on the outside around the smooth design collar. It has no crazing showing on the bottom but does have a rather odd looking craze on the inside. I would keep this teapot as a display piece and purchase another Porcelier for use because Porcelier teapots keep the tea HOT for a very long time.
This teapot has tiny crazing all over it! Inside and out, top and bottom, it's a crazy craze of crazing. Here's the "gray area" - some would say that because the inside and bottom crazing is not dark brown that it's okay to use. Some would say that perhaps you shouldn't use it. It's a sweet teapot and for those who love to collect Arthur Wood teapots, it is a nice place to stash your favorite tea or tea bags until a more perfect teapot comes along.