I recently bought a set of Korean glass stones, and several of them are badly deformed in size and shape. I have seven set aside because they are unusable (they lean to one side as such an obscene angle they become an aesthetic detriment). Incidentally, they are all white stones thus far.

Is this kind of defection or poor manufacturing common in glass stones? Or did I buy a shitty set? Note I paid $75 for the stones alone.

Does anyone else have badly misshapen stones in their set? Also, do other materials (yunzi, shell&slate etc.) have the same issue, or is it just glass?

I have a set of size 38 glass stones on the way from Korea right now. I will look for deformed stones when they arrive and report on what I find.

Yikes! $75? I have a $20 set of Korean glass stones that I got at a Korean grocery store. No misshapen stones there, but there are only 160 stones per color instead of the usual 180/181 (This will almost never be a problem unless you want to try Ing counting). They're not pretty or anything, but they're solid and have a nice weight to them. I use them for studying at home. Shingwang is a nice company that makes cheap stones. Cho Namcheul, the father of Korean baduk was once on the corporate board there; perhaps that could be considered a celebrity endorsement. They have an English storefront on the web, although I have never tried using it.

EDIT: Perhaps your stones are nicer than mine. Mine are really basic (and somewhat small), even if they are cheap and reliable.

Well, mine also came with free shipping, so who knows how much that inflated the price.

I actually don't have a board yet, but when I get it (should arrive next week) I'll take pictures and exhibit what I mean, at the same time illustrating the quality of what I bought. And yes, a few defects in a set is no big loss, but it is certainly disconcerting.


Where did you buy them from?

When you buy anything Korean go stuff, always check whether or not it is from 육형제바둑 (Six Brothers Baduk) or 한일바둑 (Hanil Baduk). These two makers may only be the credible ones. They also support boards and stones for many of Korean go tournaments.

[edit]

If my memory is correct, Hanil Baduk stones are from OEM of

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I also have experienced deformed glass stones (both Korean and Japanese),
and yes, more likely with the white stones; the black glass stones seem to be more uniform.

The "non-uniform" Korean glass stones ~US$ 30, from Samarkand.net: I emailed them, and they sent me a replacement set.
The "non-uniform" Japanese glass stones ~US$ 90, from Kiseido: I emailed Mr. Bozulich, and he also sent me some replacement stones.

Japanese slate and shell stones are much more uniform; they are at a completely different level
(much higher quality and craftsmanship) than the glass stones.
But even with some Kuroki slate stones (size 35 and under), I had experienced some "non-uniformity",
and I emailed Mr. Kuroki, and he also sent me some replacement slate stones.

Why is this, do you think? What is it about the white stones which makes them different to the black stones?

I was quite surprised to read this because I didn't see this sort of thing in any of the samples we ordered.

We get everything prepacked in the factory (which is standard practice), so we don't open the packaging for each item before sending it, but I've just opened several sets of these stones (from the same batch that your order came from) and gone through them one by one. I didn't see an example of what you're describing. Some (or in reality all) of the stone aren't perfectly symmetrical, but I couldn't find anything that looked like what you've described above.

Regardless, as it says here, if you want to get a refund or exchange anything you just have to email or call us to arrange it. You can send me some photos if you want to, and let me know what you want to do. I would like to see these stones please.

Incidentally, you're talking about the same stones we used to take this photo just yesterday: http://gogameguru.com/i/2013/01/ear-red ... inseki.jpg (and also the stones Younggil uses at his Go school in Sydney).


These particular stones cost well over double that, even if you eliminate all other costs by buying in person from 6 Brothers' factory in Korea.

_________________
David

Go Game Guru: Learn Go | How to Get Better at Go | Go Game Shop | Go Boards | Baduk TV

I found a surface on which I can showcase the deformations:



The stone on the left is normal, and the stone on the right has a flat spot which causes it to rest on an angle as shown. This is probably the most severe defect I have found so far.

_ _ _ _ _ _ _ _



These are the seven stones I have elected to be defective. The faults vary in severity as you can see, but some of them are quite bad.

I suspect there may be more and I will post here when I find more, and how many.

Ok, that's not normal.

Please either send the whole set back or figure out how many stones are like that and send those stones back to me and we'll replace whatever you send back. We'll pay for postage and will show the defective the stones to 6 Brothers to see what they say.

If you could email me please we can work out the details.

_________________
David

Go Game Guru: Learn Go | How to Get Better at Go | Go Game Shop | Go Boards | Baduk TV

Okay, thank you very much.

That's a good question, I've wondered about the same;
my guess is it has to do with the manufacturing process --
the white glass stones must go through a (slightly/vastly?) different process than the black ones?
I've never been to a glass stones factory, nor have I seen any videos, so I have no idea
how they make them. The ones shown in your photos are quite bad, and as David said,
not normal. For my 10mm Japanese glass stones set, I probably had about 1 or 2 white glass stones
with that kind of deformity. For my 8mm Korean glass stones, since they are much thinner,
even when a stone is "deformed", they physically don't have enough thickness to be
as lopsided as yours. But my guess is the Korean 8mm white stones would be in the range
of 5 - 10 with some unevenness.

PS. I like your cushion to contrast the white stones. I used a yellow-ish manila envelope
for my photos to show the manufacturers.

Thank you.

The cushion was just there and I couldn't be bothered to move it. Although I have a white wall behind so it was probably a good idea.

I've never seen a set of glass stones that didn't have a lot of irregularly shaped stones. I suspect it happens because the glass stones are made in molds from molten glass which cools into irregular shapes due to small impurities in the glass. I think the stones are not reshaped after cooling. Slate and shell stones are ground from cylindrical blanks so there is much more control of the final shape details. Traditionally the slate and shell stones were ground by hand but I wouldn't be surptised if there were a CNC process now.

As an off-the-top-of-my-head guess as to why the white glass stones have more irregularities, maybe the additives to the glass to create the white color cause more irregular cooling. Gross irregularities like the ones the OP showed might just be due to assembly line errors that weren't caught by the QC process.

If the stones come down a conveyor belt strewn all about it would be hard to catch that kind of defect I think. I have some glass stones and they all sit wonderfully. I believe I got them from Janice Kim but it looks like she doesn't sell anything anymore.

The texture of the white and black are different, so I bet the processing of them is a bit different.

As a side note to all of this, this week I took delivery of my size 41 (11.6mm) Yunzi stones from Yellow Mountain Imports. These things are quite fat and they like to wobble a bit when placed on the goban with authority. They seem pretty sturdy and uniform in shape, but...

One of the black stones was shattered into about seven shards during shipment. Interestingly, both the shrink packs of white and black stones came with a little ziplock baggie of five extra stones embedded within, almost as if they knew that a couple of stones were likely to become casualties. Also, I noticed that white Yunzi stones have a tendency to acquire dark gray hairline "scars" on their surface from rubbing against each other.

Collecting these various stone sets has been quite a learning experience. I'd love to get my hands on a slate & shell set now...

Some of the Yunzi's shatter during shipment because I believe they have internal defects from the firing process anyway. Just think of it as a QC trial by fire.

Can I just repeat that, while glass stones are never perfectly uniform, this sort of thing is very unusual with these stones.

When I showed these photos to Younggil just now he was really surprised. He has about 30 sets of these at his Go school has also used the same stones in professional tournaments. He said he hasn't seen stones like this before.

The reason why we got these stones, as a higher quality glass stones option, was that Younggil thinks they're among the best glass stones you can get at a reasonable price. We also have some cheaper glass stones available for those who want them.

Years ago, I used to sell Yunzi (and some other products) in Australia when I was still at university. The Yunzi had a much higher propensity for cracking during freight from China (even before being sent to customers) and I can remember playing someone using Yunzi where the stone shattered and pieces flew in all directions when played.

Can I also say that it's quite disheartening to stumble upon a thread like this by chance when simply contacting us directly would have seen the problem fixed quickly. What we're trying to do is already hard enough.

_________________
David

Go Game Guru: Learn Go | How to Get Better at Go | Go Game Shop | Go Boards | Baduk TV

In fairness to him, he probably didn't expect you guys to be so accommodating. In other businesses, exchanging products with manufacturing defects that don't significantly impact usability is a huge pain. Even if you buy a shiny new Macbook Pro, getting them to replace the screen if the number of dead pixels does not exceed some arbitrary number requires days on the phone even if you purchased the overpriced AppleCare (and there is no guarantee that your customer service rep will accept your request).

PS: I'm not picking on Apple. Other companies are like that, too. It's just the one that came to mind first.