Common Definitions for Art Pottery Condition and Damage
Mint condition
Mint condition should be reserved for a piece of pottery that is in “like new” condition just as it came from the factory. Mint pieces should be free of chips, cracks, repairs, damage, or signs of wear. Typical crazing and production flaws are acceptable for most art pottery classified as mint. Heavy crazing or unsightly production faults should be mentioned in the description of a piece being sold. Many sellers use the term Excellent Condition rather than Mint because professional repairs are difficult to detect without using destructive techniques such as Acetone testing.
Excellent Condition
An Excellent Condition piece is anything which is less than Mint Condition but does not contain greater than minor chips, cracks, or repair. As stated above this classification is used by many sellers to include items which could be classed as Mint.
Good Condition
This classification covers a wide range of damage beyond minor chips, cracks, or repair. A piece in Good Condition should be substantially intact.
Chips
A chip is post production damage which penetrates the clay body of the piece and results in the loss of some of the clay body material. This type of damage is distinctly different from Glaze Flakes or Hairline Cracks where there should be no loss of the clay body.
Glaze Chips/Glaze Flakes
A glaze chip/flake is a shallow chip which does not penetrate the clay body of the piece. They involve a flaking off of the glaze surface and sometimes impacts the color at the flake site.
Hairline Cracks
A hairline crack is a crack that goes into or through the clay body of a piece. If a crack can be felt with a fingernail it is a hairline and not crazing. When rubbing a suspected spot with your fingernail you should feel a slight click if there is a hairline. Often this click can also be heard in a quiet setting. Hairline cracks are difficult and expensive to professionally repair.
Crazing
Crazing is the fine crackling (spider-web-like cracks) which is present on most glazed art pottery. Crazing is in the glaze only and should not be felt. If you rub your fingernail over the crazing there should be no clicking felt as you would on a hairline crack. Crazing is due to the production process where the clay body and the surface glaze cooled at different rates. Completely uncrazed examples of Roseville and Weller are uncommom but are readily available in Rookwood. A rule of thumb for normal crazing is that the crazing should not be noticeable at a two foot distance under normal room lighting conditions.
Glaze Pops
Glaze pops are small round holes in the glaze formed during firing when air bubbles reached the surface of the glaze and burst. This is the most common form but sometimes these bubbles do not burst. Many people also call these glaze pops. A glaze pop is usually a small dimple on the surface ranging from a tiny dot to about pin head size..
Glaze Skips
Glaze skips are areas where the glaze did not completely cover the piece leaving areas of exposed clay. Glaze skips are more common on early art pottery.
Factory Mold Flaws
This is a broad category of production defects which relate to the shape of the piece. Common flaws are: Misalignment (where the two halves of the piece do not meet perfectly), this results in a distinct line at the meeting point; Misshapement (either from washed out molds, contact prior to firing, or sagging during firing). In the case of washed out molds, the first few pieces produced by a mold are of excellent quality. The quality of subsequant pieces deteriorates until the mold can no longer be used. Mold flaws are more common on Roseville, Weller, Van Briggle, and Hull than in Rookwood pottery.
Kiln Flaw/Kiln Kiss
A kiln flaw occurs when pottery in the kiln comes in contact with either the kiln wall or another piece of pottery. This often results in glaze loss the piece. If two pieces are involved one piece will have excess glaze and the other will have glaze loss. Often there will be a mixing of colors between the two pieces at the point of contact.
Firing Lines/Firing Cracks
A factory firing line is a crack that occurred during the kiln firing of a piece of pottery. Firing lines are not post production damage to the piece.
Peppering
Peppering is the minute black specks of carbon that is sometimes seen in white or light colored glazes. Peppering seems to be line related where it is common in some lines and rare in others. In our experience peppering tends to be more common in Roseville than in Weller or Rookwood. Slight peppering often does not impact the value of a piece but is less tolerated on the more expensive lines.
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