At our store, we perform quality control by re-inspecting products that have passed inspection by pottery makers and artists.
We would like to introduce you to the certain inspection standards that we use when inspecting products.
Thank you for your understanding.
Pinhole
Air and organic matter (dust, etc.) left on the base material during bisque firing may leave small holes after firing, and these small holes are called pinholes.
Generally, it is treated as a good item, but at our store we consider it to be a defective item if it is more than 2mm on the front side and more than 4~5mm on the back side.
Iron powder
When firing pottery, the iron originally contained in the clay oxidizes as it is fired in the kiln, and the black spots that appear on the surface of the pottery are iron powder.
There are many artists and potteries who create iron powder to give the appearance of their pottery, and they generally treat it as a good product.
Penetration
The pattern-like cracks that appear on the surface of ceramics are called penetrations.
Penetrations may appear as a pattern, or they may occur naturally as the pottery is continued to be used.
All of them have penetrations and the expression of the pottery changes as it is used, so we judge it to be a good product.
*If you don't want to penetrate too much, it's a good idea to seal it.
Gohonte
The light pink spots or mottled patterns that can be seen on powdered ware or white vessels are called honte.
This pink color is not due to the pigment in the glaze, but is a phenomenon that appears due to reduction firing, which creates an expression on the white vessel and gives it a taste.
This is a method of expression that has been around since the Azuchi-Momoyama period, and Hagi ware and Asahi ware are famous.
It's difficult to get them out the way you want them to, and the fun is in how each one comes out differently.
Uneven color/uneven glaze
The glaze is carefully applied one by one by hand, so the glaze may not be applied uniformly.
Traces of glaze flow and glaze puddles have long been viewed as the ``scenery'' of the pottery, so we generally treat it as a good item.
Break/fading
It refers to the bleeding, blurring, and misalignment that occur when applying patterns or paintings to vessels using inka, inhante, dyeing, etc., due to factors such as the amount of force applied during the work and factors during firing.
Fading and shading can give a richer expression to the pottery, so we often choose to use it on purpose, and we generally treat it as a good product.
Glaze splash/sauce
Painting and dyeing are carefully done one by one by craftsmen and artists with a brush.
For this reason, the glaze may splatter or drip, but glaze of about 1 mm on the surface is acceptable and is treated as a good product.
Distortion of molding
Utsuwa is kneaded on a potter's wheel, by hand, or molded using a mold.
All of them are traditional and are shaped by hand, so the shape of the finished product may differ in one point, such as not being perfectly round or slightly different in height and size.
A certain degree of fluctuation is considered to be a good product due to the unique characteristics of the pottery, but if there is too much individual variation, we will mark it as a defective product, or we will take individual photos and handle it as a separate product.
Distortion of tatara forming
Tatara molding is a method in which clay is cut into a plate of a certain thickness using cut threads, etc., and then molded by hand.
As a result, differences tend to appear in the way the pottery rises and bends.
This is a characteristic unique to tatara molding, so unless there is a large individual difference, we will consider it as a good product.
Rumble on high ground
When you set the pottery down, it may wobble a little depending on the buildup of glaze or the condition of the base of the plate.
Items with large wobbles will be removed by our shop or treated as defective items, but items with no noticeable wobbles when placed normally will be treated as good items.
If you are concerned about looseness, you can use it cleanly by sharpening it with a whetstone or coarse sandpaper.
Line scratches/rubbing scratches
If the surface has line scratches or scratches of 5mm or more in either the vertical or horizontal direction, it will be treated as a defective product.
Cracks/chips
Cracks that have invaded the base material (back side) and are more than 1 mm are treated as defective products even if there is no risk of damage.
Items with chips of 2mm or more are considered defective, and items with chips on the high ground of 3mm or more and those that are caught are treated as defective.
Book
The hole where the glaze has burst is called a buku.
It is similar to a pinhole, but its distinctive feature is that it appears where the glaze is applied.
Items larger than 2mm are treated as defective items.
Glaze peeling
Items with a diameter of 2mm or more on the front side or 5mm or more on the back side are treated as defective products.
Depositions/protrusions
Small dust or stones may adhere to the surface, creating protrusions.
Items with a diameter of 2 mm or more are treated as defective.
If you are concerned about it, you can make it less noticeable by sharpening it with a whetstone or sandpaper.