Additional words on 02/16/10
These photos were induced by this discussion. Many people experience a few pieces of crappy tea ware and bad tea along the way. People call them tuition tea ware and tuition tea (as for tea, I guess, mostly happens on puerh).
Some fake Yixing teapots are treated with paint oil (shoe paste or something of its kind) to mimic color of good clay. Once the teapot arrived, it wasn't hard to tell. In short, after I casually touched the inside of the teapot, for the whole afternoon, I couldn't wash my fingers clean :-p I should have taken a photo of my black fingers!
I took the photos a couple of months ago to show a friend and ask "can you tell what's wrong with this just by the photo". Well, I knew he knew so much better than me and could tell anyway. This teapot, I still think the shape looks nice. I washed it a bit so the "makeup" on the lid was largely "damaged". Otherwise it would "look better". Just from the photo, I am not qualified to judge the quality of clay. What's amazing (I think) about this teapot is, in the photo, the surface looks healthy sandy (of course in my unprofessional eyes). But felt in hands, the surface is actually glass smooth. Inside of the teapot appears crude clay structure like that of bricks. Maybe it was made by mixing sand and crude clay, and then polished.
Lesson learned: avoid any hint of suspicious black color!
Uploading the photos in order to get a small size image and paste the image link on a tea forum. I've found it a relevant convenient way to post photos on tea forums :D
And by the way this is my tuition shoe paste Yixing teapot. Luckily so far this happened only twice, so it's not that painful to look back. I am generally a conservative buyer, but I swear this one looked really nice in photo of the selling page. The seller was not a tea/teapot specialized seller (an expensive seller though...) so I thought there wasn't much common ground to argue with them about the clay materials. So I just kept it as a decor piece on shelf. Most of my friends are not frequent tea drinkers, so they don't realize this is an evidence that I goofed :D
6 hours ago