How to Determine the Condition of Ceramics Like an Expert
This article will explain common ceramic condition issues. It will help you determine if these condition issues are present in your ceramic object.
Always handle ceramics with clean, dry hands and remove rings or dangling bracelets. Never place pressure on small parts or applied decorative handles when picking up these objects. Remove any detachable components such a lid before handling the object. Never drag a ceramic piece across a surface when moving it. When examining the bottom of a ceramic object, lay down a thick towel or folded cloth on the table to protect it from damage.
Keep in mind that if you discover condition issues, they will not necessarily hurt the sales value of your item.
Once you’ve set up the ceramic object for examination, you should look for the following issues:
Chips, Surface Wear, and Holes
Carefully examine the item for chips by running your fingers over the surface, especially at the rim, handles, around the base, and any areas with raised decoration. Note any rough areas you find. In the photograph below you can see a small chip along the edge. Next, check to see if the paint or surface decoration is worn by looking for inconsistencies in color. Focus on areas of the object (i.e. handles) that were frequently touched. Paint layers applied after firing (over the top layer of glaze) are more likely to wear away. Is the item gilded? This surface application of gold is delicate and can rub off over time. Finally, check the bottom of the item for drilled holes, these could have been created for purposes including drainage (if the object was used to hold plants), or for electrical wiring (if the object was used as a lamp).
Check the body, rim, and underside of the object carefully for cracks. Because decoration can mask cracks, look closely at the undecorated areas, usually the underside and interior. Very fine "hairline" cracks, visible in this photograph, may not affect the stability of a piece but are still important to note.
Crazing is a network of very fine cracks or lines in the fired glazed surface. Check the entire object because crazing can develop in several different areas of a single piece. See crazing in the forehead of the ram in this photograph. Crazing results from tension on a glaze, and is important to report because crazing can weaken an object.
Stains are discolored areas (usually brown spots or dark lines) that can develop after moisture is absorbed through cracks in the glaze. This moisture absorbs dirt, grease, or impurities from the air that attract bacteria, creating discoloration. Other types of stains can result from exposure to water, food, or dirt, and are usually white, brown, or grey in color. In the photograph below, round dark areas resulting from bacteria are present on the foo dog's forehead.
Look carefully for repairs, especially on applied decorations such as handles and knops, or the hands and feet of a figurine. Scanning the surface of an object with a blacklight in a dark room can help you discover repairs. Residue, usually off-white, from glue holding the broken piece together may be present, and will fluoresce a different color than the rest of the object. Paint added in the restoration process will also fluoresce differently. Porcelain restorers also use metal staples to hold broken pieces together, but this style of repair is no longer common today.