Creating Bold Colorful Surfaces with Underglazes

Bold Colorful Surfaces

Ariana Heinzman’s assorted vases and planters, to 24 in. (61 cm) in height, ceramic, underglaze, glaze, 2019. Photo: Brooke Shanesy.

Ariana Heinzman creates bold, plant-inspired designs on her work using bright colors contrasted against black line work. As you can see in the finished image above, the results are striking! 

In today’s post, an excerpt from the March/April 2021 issue of Pottery Making Illustrated, Ariana demonstrates how she creates her bold colorful surfaces with underglazes and how her forms guide her mark making. – Jennifer Poellot Harnetty, editor.

I have more guidelines when I glaze than when I build because I am trying to hide my marks. I use matte surfaces, the color black, and patterns to draw the viewer’s eye away from my hand. I am interested in a matte finish because it flattens the three-dimensional qualities of a piece, and the color black because it makes it harder for the eye to register a shadow. The silhouette of the form becomes an illusion. To achieve a matte finish, I use underglazes fired to cone 6, as they seem to sink into the clay at higher temperatures.

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After the form is bisque fired, rinse it to get any debris off of the surface. When it is dry, you can start to glaze. Cover the interior with black underglaze by thinning the underglaze then pouring it in and out and thoroughly wiping off any drips on the outside. Use a brush to finish applying the underglaze around the top rim. For the vases, use a clear glaze over the top of the black glaze.

The palette for the exterior of each piece usually consists of two colors, one a shade lighter than the other. Brush 2–3 coats of the lighter shade over the entire form (1), then roughly sketch out the shapes of the leaves. First, visualize the shape of the leaf based on how the rim is cut, then start at the bottom of the form, but keep in mind how the shape is interacting with the cut rim at the top. This ensures a fluid pattern throughout the piece. Let the form influence the brush. Glaze on a banding wheel so the centrifugal force can also guide the brush. This is a good time not to think too hard. If you want bold lines you must be bold.

1 Apply 2–3 coats of a lighter colored underglaze as a base coat.

2 Apply quick, bold strokes of black underglaze to lay out the pattern.

Once the outline is established (2), use a second color to help with the composition. I make sure areas don’t get too dark so the line work isn’t lost. I also use two to three coats of this second color (3).

For the black line work, I use underglaze applied using three different sized brushes so that the composition is more interesting. I start with the largest brush and work down to the smallest. I only use the smallest brush for short lines; this cuts down on the amount of wavering in the line quality. These small lines add a busy quality to the composition and loosen the eye (4). I use the biggest brush to be boldest, to demand a form, to direct the eye. I use the medium brush to do something in between. I make each line based on the previous line and quickly visualize how they will come together, but that is it. If I let myself linger too long, the surface looks stale or muddy.

Give every line except the tiny ones another coat. This solidifies the line and also its identity. For the first time in the process, I become aware of the final product. The cone-6 firing completely affirms the identity of the vessel.

3 With bold strokes, apply 2–3 coats of a second color next.

4 Apply multiple coats of additional line work in varying thicknesses.  

Relinquishing control over the final product while setting up guidelines for the process is necessary for me to fully enjoy clay. I do not pretend to know what I am doing, just the next step. “The man that knows something, knows that he knows nothing at all”—Erykah Badu.

Ariana Heinzman earned a BFA in ceramics from the Rhode Island School of Design. She currently lives and works on Vashon Island with ties to Cincinnati, Ohio. She is represented by J. Rinehart Gallery in Seattle, Washington. Learn more about her work at

    • Ash N.

      Hi Jan, the finished piece is located at the top of the article. It is one of the blue pieces in the upper left corner of the photo. – CAN Staff

  • Scott M.

    What brand of underglazes do you prefer? Do you make your own? What clear glaze do you finish with?

    Thanks, Scott

    • Hi Scott, it looks like Ariana uses Amaco underglazes based on the tops of the bottles in image 1, but I could be wrong. – CAN Staff

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