How Can You Tell If Pottery Is Polish?

What is polish?

Ceramic polishing is the process of smoothing and buffing the surface of ceramic pieces to create a glossy, mirrored finish. It enhances the natural beauty of the clay and glaze by removing small imperfections and scratches from the surface. According to Unveiling Brilliance: The Art and Science of Ceramic Polishing, “Ceramic polishing is a transformative process that unveils the true potential of ceramics, turning them into gleaming works of art.”

Polished ceramic surfaces have a smooth, glossy look and feel, while unpolished surfaces tend to be dull and porous in texture. The purpose of polishing is primarily aesthetic – to enhance the visual appeal and light-reflecting properties of the ceramic. It also creates a non-porous surface that is easier to keep clean. According to the article WHICH METHODS OF CERAMIC POLISHING AND THEIR BENEFITS, polishing can “remove the adhesion on its surface, flatness improvement, get a thinner metallization layer, etc.” The uniform smoothness accentuates the natural colors and patterns of the clay and glaze.

Visual indicators

One of the most obvious ways to identify polished pottery is by looking closely at the visual qualities of the surface. Polished ceramic often has a very smooth, glossy surface with a reflective sheen. This is achieved through the process of burnishing or rubbing the clay with tools while it is still wet or leather-hard to compact the surface and create a uniform smoothness.https://www.floridamuseum.ufl.edu/histarch/ceramic-types/introduction/ The surface of properly polished pieces will lack any visible tool marks, scratches or other blemishes. Light will reflect evenly off the polished surface, helping highlight the smoothness. Unglazed pottery that has been well-polished takes on a glossy, glass-like finish. If you look closely at the surface and can see thehints of tool marks or an uneven, pebbly texture, then it is likely unpolished or partially polished.

Touch Indicators

One of the key ways to identify if pottery is polished is by feeling the surface. According to issue 8, polished pottery will have a smooth, almost slippery feel due to the friction and heat of the polishing process sealing and compressing the clay particles.

Well-polished pieces lack any prominent texture or irregularities that are common with unpolished pottery. As described in The Importance of Touch: Conveying Process Through Tactility, polished surfaces should feel uniform and consistent to the touch.

So if a ceramic piece has an ultra smooth, slick sensation devoid of any substantial surface variations, that is a strong indicator it has been polished.

Sound indicators

One way to identify if pottery is polished is by the sound it makes when tapped. Polished pottery tends to produce a high-pitched ringing sound compared to unpolished pottery, which gives more of a dull thud. This is because polishing creates a smoother, less porous surface that reflects sound waves instead of absorbing them. According to research on sound absorption properties of ceramics, materials with lower porosity like polished pottery have reduced ability to dampen sound waves, leading to the brighter, ringing tap [1]. So if you gently tap a ceramic piece and hear more of a ringing tone without much deadening, it is likely polished.

In contrast, unpolished ceramic with more surface porosity absorbs sound instead of reflecting it back, giving it that classic duller thud sound when tapped. Studies have shown that increasing microscopic surface roughness and porosity in ceramics enhances their sound absorption across wider frequency ranges [2]. So if you tap an unglazed ceramic and hear a low thud, that is a key auditory indicator it is unpolished.

Making Polished Pottery

There are several techniques used to make polished pottery. The most common is burnishing, which involves rubbing the surface of leather-hard clay with a hard tool to compress the clay and create a smooth, shiny surface [1]. Burnishing can be done by hand or by using a burnishing tool. Some common burnishing tools include stones, glass, spoons, and specially shaped tools made of steel or stone [2].

To burnish clay, you first shape your piece and allow it to dry to a leather-hard state. Then, rub the surface in a circular motion, applying even pressure. Start with coarser tools first, then refine with smoother tools to achieve higher shine. It takes time and repeated burnishing to get an evenly polished surface. Some clays burnish better than others – dense clays with fine particles work best.

In addition to burnishing, some other techniques for polished pottery include:

• Glazing – Applying a glossy glaze results in a shiny surface after firing
• Waxing – Rubbing wax on bisqueware fills pores and creates sheen
• Polishing – Using friction to smooth and shine an unfired or fired surface
• Buffing – Using an abrasive wheel or drill attachment to finish surfaces

Achieving a polished pottery surface takes patience, the right clay and tools, and practice. But the resulting luminous, glass-like finishes are worth the effort.

Unpolished vs Polished

The key differences between unpolished and polished pottery relate to their visual appearance, how they feel to the touch, and the sounds they make.

Visually, unpolished pottery has a matte, textured look with the natural texture of the clay body showing through. Polished pottery has an ultra smooth, shiny, and reflective surface from polishing and glazing. The polished surface highlights intricate designs and patterns.

To the touch, unpolished pottery feels textured and porous. Polished pottery has an incredibly smooth, glass-like feel from the polished glaze surface. The smoothness makes polished pottery feel cooler to the touch compared to unpolished.

Unpolished pottery makes a duller sound when tapped due to its porous nature absorbing vibrations. Polished pottery has a much sharper, ringing sound from the hard glaze surface.

Polishing serves both aesthetic and functional benefits. The smooth polished surface lends a luxury, high-end look and feel while also making the pottery non-porous, easier to clean, and more durable. However, polish can make pottery slippery and prone to showing fingerprints. Many prefer the natural, organic look and feel of unpolished.

Authenticity

Determining whether a piece of Polish pottery is an antique original versus a modern reproduction can be tricky. Here are some tips for spotting the signs of true antique Polish pottery:

Antique Polish pottery will have slight imperfections in the glaze, colors, and patterns. Modern reproductions tend to have more uniformity since they are mass-produced. Subtle variations like blurred lines or uneven coloring indicate an antique original handmade piece.

Antique Polish pottery often has evidence of wear and tear like chipping, cracking, or fading which occurs over decades. Reproductions will look pristine and new.

Check markings like stamps, signatures, and dates that can help authenticate it is decades or centuries old. Many reproductions lack these identifiable antique marks.

There are some testing methods that can be used to date Polish pottery and confirm its age:

– Thermoluminescence testing which analyzes the last time the clay was fired
– Ultraviolet light testing to check repairs and alterations
– Dating the clay paste and glaze materials
– Comparing to verified museum examples
– Consulting an expert antique appraiser

These scientific testing methods can definitively determine the age and authenticity of Polish pottery. When in doubt, consult a reputable appraiser.

Caring for Polish

Polish pottery requires some special care to keep it looking its best. According to the Polish Pottery House (https://www.polishpotteryhouse.com/pages/information-care-history), gentle cleaning is recommended to avoid scratching or damaging the polished finish.

Handwash polished pieces whenever possible using a soft cloth or sponge and mild detergent. Avoid abrasive scrubbers or scouring pads that could scratch the surface. If cleaning in the dishwasher, use a gentle cycle and be sure to thoroughly rinse and dry the piece when finished.

Try to avoid banging polished pottery against other objects or utensils to prevent chips and scratches. Store pieces carefully stacked with padding in between to protect the polish. According to Artisan Moments (https://artisanmoments.com/2019/07/08/how-to-care-for-your-handmade-polish-pottery/), you can touch up small scratches with a polishing compound made for ceramics.

Notable examples

Polished pottery has been created around the world for thousands of years. Here are some notable examples of famous polished wares through history:

Ancient Greek Black-Figure and Red-Figure pottery – These styles from around 700-300 BCE featured iconic black or red figures on a polished orange/red background. The figures were intricately drawn and the background was highly burnished.

Tang Dynasty Chinese pottery – Produced in China between 618-906 CE, these pieces often had crystalline glazes over the polished bodies, exhibiting incredible depth and brilliance.

Aztec Polished Ware – The Aztecs from the 14th-16th century CE produced polished orange wares, some with black or white designs. The polishing techniques gave them a smooth, lustrous finish.

Carolina Creamware – This historic American pottery from the 1800s was salt-glazed and burnished, often with elaborate carved designs. It was highly polished to a shine.

Regional polishing techniques also abound. Japanese raku wares are hand-polished by rubbing with a soft cloth. Siamese celadon often has polished unglazed areas to contrast with the crackled glaze. Native American pottery in the Southwest United States is traditionally polished with stones for a signature appearance.

Summary

To summarize, there are several key indicators that pottery is polished. Visually, polished pottery will have a smooth, shiny surface without visible tool marks. It will feel smooth to the touch without any grittiness. Polished pottery also has a clear ringing sound when tapped. While polish provides an attractive look, it can also hide attributes that help date and authenticate pottery. Care must be taken to preserve the polish through proper handling and display. Recognizing polished pottery is important for collectors and researchers seeking to understand the origins and history behind ceramics.