In the Studio: Piercing a Project

I love piercing pots. I was first inspired by windows that looked dramatically different from the inside versus the outside. I wondered what the effect would be of making windows on a ceramic object.

Boxes were the first object I experimented with piercing, as they have an architectural quality to them. I liked the results, but have continued to develop the process over the years, eventually using it on other objects such as vases and colanders.

1 Create a template on durable, thick cardstock or similar. Use the template and a sharp knife to mark your piece before making any cuts into the firm clay.

2 You can use a ruler to straighten and reinforce the lines.

Adding Pierced Windows

Piercing is only as exact as your measuring and marking. I mark all my pieces with a template before I make a single cut (1, 2). Before I begin to cut, I make sure the clay is firm enough and will not distort under the pressure of a knife (3). Only after I have finished making all the cuts do I remove the cutouts very carefully. I don’t remove them after each cut so that I don’t distort any of the windows during the remaining cutting process (4). I usually pierce and then rib over the piercing. This helps compress the corners and walls and alerts me to any potential issues such as tears, cracks, or thin areas (5).

3 As you begin to cut, make sure the clay is firm enough and will not distort under the pressure of a knife.

4 Once the cuts are made, remove the cutouts very carefully. Don’t remove them after each cut or the piece will distort.

5 After piercing, rib over the form to compress the corners and walls, and find potential tears, cracks, or thin areas.

At workshops, people often ask if I have any tips for successfully piercing a vessel. Here are a few that I’ve learned the hard way:

  • Use the right cutting tool for the job. A dull knife will only give you trouble.
  • Don’t ask too much of your clay! Cutting holes in your pot can weaken the walls. If you’re firing your piece to a high temperature, that could cause the walls to slump (melt) or warp.
  • If your walls are too thick, they will be difficult to cut and, in turn, it will be difficult to extract the cutouts.
  • Mind your corners and don’t precut them. Think about a ketchup packet, where a notch on the edge helps you open the packet. The same idea works against you in clay. If you create a cut corner, you may cause a potential crack.

Excerpted from Mastering Handbuilding by Sunshine Cobb and published by Voyageur Press, an imprint of The Quarto Group. To learn more, visit The book is available for purchase from the Ceramic Arts Network Shop at See more of Sunshine Cobb’s work online at or on Instagram @shinygbird.

  • Wendy C.

    I would like to find a carving knife like the one you’re using in this demonstration. Would you mind helping me make that connection? Thank you! 🙂

Leave a Reply

You must be logged in to post a comment.

Enter Your Log In Credentials
This setting should only be used on your home or work computer.

Larger version of the image
Send this to a friend