Decorating Through Disassembly: Jeff Campana’s Sliced and Spliced Porcelain Pottery

Cut and paste your pottery to make exceptional surface designs!

More than meets the eye—the lines on Jeff Campana’s pots go beyond just scratching the surface.

There are many, many ways to put lines onto pots – carving, fluting, painting, drawing – but, I have to say, I had never seen anyone doing it quite like Jeff Campana. Jeff takes his well-thrown porcelain pots, chops them up into pieces, and then reassembles them. Then to top it all off, he uses glazes that pool in the seams. If you have ever worked with porcelain, you know that it is already challenging enough to handle. To put it through the extra stress of being cut up and reassembled—and still end up with such refined finished pieces—is pretty darn remarkable.

In this post, an excerpt from Working with Porcelain, Jeff shares his technique and how he arrived at such a labor intensive process in the first place. – Jennifer Poellot Harnetty, editor.

People tell me all the time that I’m crazy for making these pots. The time, effort, and staggering loss rate involved with my work make it perhaps a risky business idea, but I think it’s a worthy artistic endeavor nonetheless. The idea rattled around in my head for years before I actually found the courage to make it a reality. I’ve found that the things that seem almost impossible to make can provide the most richly rewarding experience to the maker and viewer alike.

Five Great Decorating Techniques

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Decorating through a process of dissecting and immediately reassembling my pots, I make connections between structure, process, surface, and form. More than simple incising, my decoration consists of lines and the architectonic plates between them. Small wanderings in the alignment subtly point out the complexity of process, while the continuity of throwing lines and trim marks allow us to see these vessels with the comfortable familiarity of the simple thrown pot. I share this process in hopes that it inspires others to try their own seemingly insane ideas and find that in fact they are possible, and worth pursuing.

Fig.1 Make reference marks using a Decorating Disc and a compass.

Fig.2 Connect the dots with curved cuts made using a box cutter.

Prep Work

The process starts with a leather-hard, thrown and trimmed bottomless form made from cone 6 porcelain. The form is ready to be worked on when the clay is firm to the touch, i.e. pressure from my fingertip doesn’t leave a mark, but my fingernail will easily leave one. At this stage, the clay is rigid but not brittle. This is important because I don’t want the clay to lose its shape in the process, and as accuracy and clean lines are important, the clay can’t be so hard that a knife crumbles the edges as it cuts through the form.

I mark the pot with some dots to guide my cutting (figure 1). I use an MKM Decorating Disc for the radial divisions, and a compass without its pencil to measure height. Alternating high and low marks, eight in total, result in a finished form that looks like it has four sections or is divided into quadrants.

Disassembly Required

I flip the pot upside down on the Decorating Disc to begin cutting. Using a box cutter, I carefully cut an arching pattern, connecting the dots (figure 2). I do this freehand, and it did take some practice to get this right although I don’t always hit the dots exactly. Once this is done, the top portion is set aside and work begins on the bottom (figure 3).

Fig.3 Separate the bottom of the pot from the top after making the cuts.

Fig.4 Cutting the bottom in half at the lowest point of the arches.

Fig.5 Coat the walls with joining slip and reassemble the parts.

Two vertical cuts on opposite sides divide the bottom part in half (figure 4). I gently sponge the sharp edges to soften them. Using a finely serrated rib, I score the edges, then brush a special joining slip into the grooves and sponge off any excess.

I quickly press the two halves back together, making sure there is a continuous connection along both seams (figure 5). The bottom portion is set aside to allow the slip to set up and I switch back to focusing on the upper half.

Using the Decorating Disc once again, and working with the piece upside down, I make four vertical cuts, one at the top of each arch (figure 6). For a more dynamic lip line, I carve some of the clay from the middle of the rim on each part and carefully sponge it until no line is visible (figure 7).

Each piece is put back in its place so that parts don’t get jumbled. Once all four parts of the top section are prepped for assembly, I set them aside and move on to finishing the bottom (figure 8).

Fig.6 Place the top on the disc upside down, make four vertical cuts.

Fig.7 Carve down the lip in the middle to create a curve.

Fig.8 All four parts of the top, with rims facing the middle, are ready to be joined.

Two cuts are made on the bottom section, just like before but on the other corners (at a 90° angle from the first cuts), then the edges and topsides are sponged and scored.

For each pot, there is a separately thrown and trimmed clay disc that floats freely in a groove trimmed into the inside wall of the foot ring (the groove is visible in figures 4 and 5). I do this because it results in a very unique, interesting termination for the lines carved into the pot. In the final assembly of the bottom portion, I carefully select the best fitting disc from a stockpile of various sizes I have on hand, kept in the perfect leather hard state in a damp box (figure 9). If one does not fit, I narrow the diameter of a disc by spinning it in my hand and going over the edge with a damp sponge.

Fig.9 A stockpile of various bottom discs with differing diameters.

Fig.10 Insert the disc into the trimmed groove to check the fit.

Fig.11 An exterior view after assembling the bottom two halves.

I insert the disc into the groove and check that it fits snugly and that the two halves can go back together nicely with the disc in place (figure 10). Joining slip is applied to the two seams and the excess is sponged off, being careful to keep slip out of the groove. After everything is carefully lined up, I squeeze the seam together, again checking that the seam is well joined (figure 11).

Now it’s time to begin attaching the top segments one by one. I score and slip each side and carefully attach (figure 12). The placement is crucial. If the part is placed too far out in relation to the bottom wall, the pieces will not meet up when I get to the last connection. The angle needs to be perfect as well so that the seams connect from the top to the bottom. Before slipping the piece together, I dry fit the parts, getting a feel for their exact position.

The lid is thrown at the same time as the body of the pot, allowed to reach leather hard, and assembled the same way as the body, but in this case, the disc that fits into the center opening on the lid has a knob thrown onto it. I cut the lid in half one way (figure 13), clean it up, score it, and reassemble it. While the slip sets up, I move to the other lid. I learned early on that it’s always a good idea to make at least two lids for every pot, just in case something happens to one of the lids in the drying and firing. If both turn out, I can pick the one with the best fit, or the one that looks the best.

Fig.12 Here, top sections are placed one at a time. The rim’s curve is visible.

Fig.13 I bisect a prepared lid form. The center opening has a trimmed groove for a knob/disc combination.

Fig.14 I rejoin the two sections, bisect it in the other direction and insert the disc end of the knob into the groove.

Returning to the first lid, I cut it in half at a 90° angle to the first cut, clean it up, and test fit the knobs (figure 14). I keep a stockpile of knobs on hand just like I do with the discs. I slip the two parts and attach them firmly. After finishing the second lid,the drying process begins. When working with porcelain that’s been assembled from various parts, careful drying is essential to the survival of the piece. I keep the jar and its lids loosely covered, drying to bone dry over the course of at least five days.

Joining Slip for any Clay Body

I make joining slip by deflocculating my clay throwing scraps. Deflocculation is basically changing the ionic pull of the water. This causes the particles to repel each other, allowing a liquid consistency with much less water than it would otherwise take.

Deflocculating the slip has a number of advantages:

  • It reduces the shrinkage of the slip, which reduces the chance of cracks in the drying.
  • It gives the slip a flowing quality that helps it fill the tiny score marks completely.
  • It makes the slip very tacky, so parts joined together have an immediate bond.

I take the big chunks from my splash pan right after throwing. Basically, it should be a little bit wetter than plastic clay. Add a few drops of Darvan #7 to a pint of it. Blend the mixture with a hand-held mixer until smooth. You should notice that it immediately loosens the mixture to a runny liquid. It should be the consistency of honey. If it is too thin or runny, add some more clay. If it is too thick, adda few drops of water. A batch of this should last months.

Campana Mid-range Porcelain Cone 6–7
EPK Kaolin


Tile #6 Kaolin 15
OM4 Ball Clay 10
Feldspar 35
Silica (325 Mesh) 20
Add: Bentonite 3%

Jeff Campana received his MFA from Indiana University in Bloomington, Indiana. To see more of his work visit

 **First published in 2010.

  • Jeff-
    Love your work! I drink coffee out of one of your mugs almost every single morning. It’s definitely my favorite.

  • Joan – I trim it in there with a trimming tool.

    Saabirah – If a pot cracks in any part of the process there’s only one thing to do with it, which is to scrap it.

  • I love the way your process defines the grace of the shape and then further defines it again with the glaze. Beautiful. I followed your instructions all the way but how did the bottom grooves got there for accepting the disc.

  • Janice W.

    Natalie from Perth. I am also from Australia and i believe that we use ‘Dispex’ as a deflocculent here.

  • Carole,

    Yes, the seams are visible inside and out – one of my favorite aspects of my work. I rely quite a bit on the glaze seeping into the seams to seal and strengthen the pot for use.

  • Carole F.

    Do your pots retain the grooves on the inside that they have on the outside where they have been seamed? Or do you fill/smooth the grooves on the inside?

  • I too use porcelain & love it…..have benn altering & cutting for years but nothing like your beautiful work!!!!!!! I agree with the comments above….

  • Leisha H.

    Wow! I’ve been working with Porcelain off & on for years and steady the past two. I live in Colorado where our climate is an arrid desert. I’m in awe of you, your tenacity, patience and precision has produced amazing results! Thank you for sharing.

  • Barbara P.

    Deflocculant … What is Calgon? I bought two bottles of Calgonite, thinking to use it in making terra sigilata. I thought that was the purpose, to keep the molecules from adhering.

  • I guess, as Suzy just wrote, the substitute in your part of the world for darvan is called Susset. It is not something you can find at the grocery store or anything, you have to get it from a ceramic supply place. Basically it is a polymer dispersant or deflocculant. Sodium Silicate is the widely available substitute, which I’ve heard can be purchased at pharmacies under the name “waterglass”. Darvan is just a more high-tech, better way to do the same thing that Sodium Silicate does.

  • HI
    I think your work is stunning, and the glazes are also very complimentary
    I come from Perth and dont know what DARVAN is, one of the ingredients used in slip making, obviously a brand name for something
    Please let me know what that is

  • Pauline – here in New Zealand there is a deflocculant called Susset – maybe you have that in the UK?

  • Thanks for the comments guys, here’s some answers.

    SC – I used to use Kona F-4 but now I use Minspar 200 which I think is pretty much the same thing.

    Pauline – Darvan is a deflocculant. I’m sure there is something like Darvan widely available in Europe, you could use Sodium Silicate as a substitute.

    Len – I still lose about 50% of what I originally throw. The box cutter is a small snap-off blade utility knife. I also have been using exacto knifes for smaller scale work. I have used 5 different midrange porcelains, and still actively use two – one is for small work and then I have one with less shrinkage and pyroplasticity for larger work.

    Olga – The plastic sectioned thing is called a MKM Decorating Disc. They come in packs of two (one odd numbers, one even numbers) and are not cheap. I would not try to make my own though.

  • Subscriber T.

    Hello,Jeff.Did you do by yourself that plastic sectioned weel? If it is possible to bye it in a shop,please,tell me its name.Thanks.

  • Leonard C.

    Wow, sweet work, I luv it…do you actually lose a lot of pieces? or was that during your earlier designs iterations getting the method down …when you say box cutter you mean razor?…have you tried with other clay bodies?

  • Pauline H.

    I’m very interested in the deflocculated slip – what is Darvan please? We don’t seem to have this in the UK. Do you know of an equivalent?

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