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Building up Luminescent Surfaces with Commercial Underglazes


The vivid surfaces on this teapot were achieved by layering and sanding away underglazes.


Wow! The first time I saw photos of Jeffrey Nichols’ pottery (and pretty much every subsequent time), I couldn’t help but say wow. I’d suspect it is a fairly typical reaction to the vibrant (and vibrant is a bit of an understatement) surfaces of his vessels. I still haven’t even seen Jeffrey’s work in person, but I am guessing that reaction would be an all-caps WOW!


Of course, after the wows are out of the way, the next thought that comes to mind is “how does he do that?” Well, today, Jeffrey kindly shares his technique with us. And to that I say woohoo! – Jennifer Harnetty, editor.


Trying to develop one’s own voice in clay certainly can be a challenge. As a young potter, I spent my time learning all the basics, such as clay and glaze formulation and of course throwing paper thin vessels.


After years of honing my skills, I finally realized that traditional ceramic processes were getting in the way of my ideas. I wasn’t achieving the results I wanted with my ceramic art. Don’t get me wrong. I think it is critically important for potters to have a comprehensive knowledge of the material and possess strong craftsmanship skills, but my true artistic voice did not develop until I started making work that began with an idea first, not a process.


Inspired by the concept of wabi-sabi, the Japanese aesthetic where beauty is found in things that are imperfect, I began looking for inspiration in non-ceramic surfaces. I found it in surfaces like weathered painted wood and brick, as well as in nature, within fall leaves and spring flowers. I wanted to create works that evoke the same kind of impact a Rothko painting possesses.


The following is the process I developed to replicate these kinds of surfaces.I start my process with an earthenware clay body and throw it into a teapot, bowl or vase. Then using a surform tool, I create facets on the leather hard form. After the piece is bone dry, I bisque it at cone 02 and then began spraying the vessel with multiple layers of Amaco Velvet underglazes. Essentially, I use the velvets as a high-frit engobe.


Safety with Spray Guns
It is important to maintain a safe and clean working environment while doing this process. Always wear a respirator with a P-100 rating and, if spraying the underglazes, use a spray booth with at least 1000 CFM. I also have a second ventilation system in my studio.


You can also layer the underglazes by sponging them on if you do not have access to a spray booth. I would recommend wearing gloves if you take this approach.


After the underglazes have dried, I begin sanding through the different layers exposing the other colors, as well as the earthenware clay body underneath. Again, remember to wear a respirator! I start with 320-grit sandpaper working to a 600-grit surface. I then fire the piece to cone 04 holding it at maturation for ten minutes to create a strong bond between the clay body and the underglazes.


It is important to apply this surface only to the outside of vessels or in areas that do not come in contact with food or drink. When fired, the velvets have the durability of a matt glaze, but are not food safe. I then apply a food-safe liner glaze to the parts that will come in contact with food and fire the vessel again. After this firing, I coat the underglaze surface with a food-safe oil sealant and wax used by utilitarian wood turners. This seals the outside surface and makes it fairly durable.



Finding your own voice may be as simple as starting with an idea or a specific image. Then try to figure out how you can achieve that in clay. In that way you are not only developing new approaches to the material, but you are working toward creating your own aesthetic and voice.




Learn more great handbuilding techniques! Download your free copy of Underglaze Users Guide: How to Use Ceramic Underglazes to Add Color and Graphic Interest in Your Pottery Projects.