Mugs are constant companions, vessels that we carry with us from task to task. A handmade mug is an opportunity to enrich someone’s day-to-day life with an intimately scaled piece of functional art. My work is carved with a floral design that portrays women connecting and expanding their influence on the world around them. The carving ventures into unexpected places, dropping into the interior of the form.

In this article, I’ll walk you through how to create vibrant and tactile pieces by carving and inlaying underglazes. I’ll also explain a technique I use to obtain a clean line between two different glazes using latex resist.

Finished mug by Kirsty Kash.

Preparing Your Pot for Decoration

Consider using a smooth, white clay body. I like Plainsman Clays’ Polar Ice, a cone 5–6 porcelain clay body. What draws me to this clay body is its fine-grained texture, which makes it ideal for carving, and the luminous white surface that brings out the vibrancy of underglazes.

I suggest starting with a small and simple form. At first, avoid handles and dramatic curves, as they make carving trickier. When throwing, do your best to maintain an even wall thickness of approximately 3/16 inch (4mm) throughout the pot to prevent accidental carving through thin areas. Before removing your piece from the wheel, clear away the excess slip and smooth the surface with a flexible metal or rubber rib. Trim the foot.

Applying Wax Resist

When your piece is leather hard, use a foam craft brush to apply a thin, even coat of wax resist to the exterior of the pot (1), covering all parts exposed to air, including the bottom and handle. Plainsman Clays’ Wax Resist Emulsion R is a good option for its smooth application and hardening properties. 

After about 10 minutes, the wax should be cured and ready for carving and inlaying. Tip: Placing a soft piece of plastic inside the cup while carving helps to slow the drying process.


Planning a Pattern

Next, use a permanent marker to map out your design and envision how it will flow around the form before carving (2). This method enables you to work out your composition and make any necessary adjustments before carving.

The design that I carve is inspired by doodles I used to idly draw in the margin of notebooks. I encourage you to carve a pattern or motif that is meaningful for you!

 

1 Start with a simple form with even wall thickness. Apply a thin coat of wax resist. 2 Plan your surface design with a permanent marker before carving. 3 Using a sharp carving tool, carve through the design about 1mm deep. 4 Continue the carving all the way around the pot.

Carving the Pattern

Carve when the clay is a chocolate leather hard—firm enough to handle but still scored easily with a fingernail. If the clay is too soft, it’s challenging to maintain control of the carving tool, it may leave burrs, and it can be easy to carve through the pot by accident. It is best to stop and wait until the clay is firmer. On the other hand, if the clay is too dry, it can lead to hand strain, release clay dust into the air, and will quickly wear down carving tools.

I use the DiamondCore Tools P1 Curved V Tip and carve about 1mm deep. Begin carving at the top of the piece (3), which will dry first. Turn it in whichever direction feels most comfortable and handle the piece gently, as areas that have already been carved are delicate (4). Tip: As you carve, collect the small ribbons of clay in a container of water to prevent releasing dust into the air. Allow your piece to dry slowly under thin plastic for several days.


Inlaying Underglaze

It is best to inlay underglaze at the bone-dry stage because the clay accepts the material evenly.

Experiment with colors and combinations that speak to you! For smooth gradients, mix colors on a palette, gradually incorporating a little bit more of the next color as you go (5). Some colorants (such as those containing cobalt) overpower other colors so it may take some experimenting to accomplish a smooth gradient transition. Avoid applying in straight bands of color and feather the edges into each other to blend colors. To reduce waste, only paint underglaze on the carved areas. Apply two coats to achieve opacity. 

 

5 Apply 2 coats of underglaze over the carved areas, blending colors together. 6 Remove the excess underglaze with a damp grout sponge. 7 Tidy stray underglaze using a stylus or needle tool. 8 After bisque firing, apply latex resist to the interior rim.

Removing Excess Underglaze

Once the underglaze is dry, use a clean, damp sponge to wipe away any underglaze that remains on the uncarved areas (6). My preferred sponge is a grout sponge from a hardware store cut into thirds as it removes just the right amount of material. Submerge the sponge in clean water then squeeze as much water out of it as you can so that it won’t remove too much clay material or smear the underglaze. Turn to a clean part of the sponge for each wipe. Carefully inspect the piece for any underglaze left outside of the carved areas, as it will be difficult to remove after bisque firing. 

Next, use a stylus tool from DiamondCore Tools to carefully tidy up stray underglaze (7). Finally, bisque fire the piece.


Glazing

My work features a rim that is folded to the inside. This allows me to bring the design from the exterior of the mug to the interior and creates a natural termination point for the outside of the pot that is different from just the rim.

 

9 Pour a food-safe liner glaze inside, coat the interior, then pour it out. 10 Use a sponge to dab excess glaze off of the latex. 11 Peel off the latex resist, leaving a clean glaze line. 12 Coat the exterior in clear glaze, then swirl the rim at an angle to coat the inner lip.

Robin's Egg Blue Glaze RecipeTo achieve a clean line between two different glaze colors, use latex resist. Thin it with a bit of water and apply it using a synthetic brush to the dropped rim and a little bit over the top edge of the mug (8). When the latex is dry, pour in a liner glaze (I use Robin’s Egg Blue glaze, see recipe to the right) and pour it back out (9). Sponge off any beads of glaze (10), and peel off the latex immediately (11) to avoid dry glaze materials being released into the air.

Apply a clear glaze to the exterior of the mug by dipping it into a clear glaze (12). Once dry, apply clear glaze to the interior part of the rim by carefully dipping that part of the mug in the glaze upside down at an angle (this takes practice!) or by brushing it on. Finally, glaze fire to temperature.


Final Thoughts

As a material, clay takes in the touch of a maker and holds onto the information, becoming solid when fired. When someone’s fingers explore the texture or they see the vibrant inlaid colors, I hope that the details in my work will nudge them to share their authentic self with the world.

Kirsty Kash lives with her family in Winnipeg, Manitoba, where she works in her home studio. You can find her on Instagram at @kirstykash or on her website at www.kirstykashceramics.com.
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Topics: Ceramic Decorating Techniques
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