Laying it on Thick: Decorating with Slip Inlay on Bisqueware

Blue and White Jar, 23 in. (58 cm) in height, porcelain with inlayed cobalt pigments.

If you frequent Ceramic Arts Daily, you may be familiar with the term Mishima because we’ve posted several different variations on the technique in the past. Mishima is a traditional Korean surface decorating technique that involves inlaying a colored slip into incised lines on leather-hard clay.


I have found another variation on Mishima that I just had to share today. In this post, ceramic artist Steven Young Lee explains the Mishima variation that works best for his work. Instead of working with leather hard clay, Lee lays a thick coating of slip onto bisqueware and then scrapes it off with a metal rib. I for one, was excited to see this variation, because I have had trouble with gouging the leather hard clay with my rib when I tried the more traditional method. I know, I know, practice makes perfect, but I still plan to explore this technique. After all, there’s more than one way to inlay a slip. – Jennifer Harnetty, editor.


Most of my work begins on the wheel with traditional forming techniques. Pieces are wheel-thrown in either one or two parts using Archie Bray grolleg porcelain or dark stoneware and are manipulated at further stages of the process. Each body of work utilizes a different surface treatment that is chosen based on conceptual or aesthetic necessity and fired to the appropriate temperature.

<p>Birds of North America, 18 in. (46 cm) in height, porcelain with inlayed cobalt and decals.</p>

Birds of North America, 18 in. (46 cm) in height, porcelain with inlayed cobalt and decals.

The blue and white pieces are made with porcelain clay and fired to cone 10 reduction. For the decoration I use an inlay technique, drawing into the surface of the leather hard clay with a set of small woodcarving knives. The timing and choice of clay is crucial to get a clean line; the porcelain provides a smooth clean surface to draw on but if the clay is too dry the edges will tear and crumble. The drawing takes about 2-3 days during which time the work is kept in a plastic tent to maintain humidity and protect the drawn lines.In the traditional Korean inlay process (Mishima), the slip is added to the leather-hard piece and then scraped off when dry to reveal the inlayed colored clays. I’ve tried this method in the past but found that I would often lose some of the detail in my drawing. I now bisque-fire my pieces first, sand the edges down with sandpaper, and then fill in the carved lines with cobalt/porcelain slip. After the slip dries on the surface I can scrape off the excess with a metal rib to be reconstituted and used again. The surface is wiped clean of excess slip and then glazed with a clear glaze.

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White Slip Base:
Grolleg 30
EPK 15
XX Saggar 25
Neph Sy 15
Flint 15
Total: 100%


After a piece has been carved and bisque fired, inlay slip is applied and allowed to dry before it is removed with a metal rib. This allows Lee to preserve the precision of the carving.

After a piece has been carved and bisque fired, inlay slip is applied and allowed to dry before it is removed with a metal rib. This allows Lee to preserve the precision of the carving.

Inlay Slip Colorants:
Blue- Cobalt Oxide 1-2%
Black- Cobalt Oxide 4%
Manganese Dioxide 4%
Red Iron Oxide 6%
Chrome Oxide 2%
  • Lowell S.

    I have used this technique with both low fire and high fire ware. I have never attempted to do this with bisqueware only with ware at the leather hard stage. I have not had any troubles with slips or underglazes popping out. I get great fine clean lines and no bleeding.

  • Peter H.

    Just happened across the paper
    “An Archaeochemical Microstructural Study on Koryo Inlaid Celadon” at

    This states that:”The close similarity between glaze and black inlay in the microstructure
    suggests that the glaze material was modified by adding clay with high iron content, such as
    biotite, for use as black inlay.”

    I pass the info on for what it’s worth. The idea certainly provides an interesting contrast with
    Steve’s use of coloured body-slip.

  • Jackie F.

    I do inlay in cone 6 porcelain. I started with 10% mazerine stain in the same clay body, on greenware. I had a lot of trouble with the slip popping out of the incising during the glaze firing. Nothing I tried seemed to solve this problem. When I started using underglazes, the ones that didn’t have cobalt in them worked beautifully, never any problem. Only the navy blue one did the same popping out thing. I still haven’t figured it out. However I can recommend using underglazes for cone 6 on greenware, especially if they aren’t dark blue!

  • I use this technique for engraving steelhead fly and steelhead (the fish) onto white porcelain bodies. I’ve had great success with cone 9 oxidation but very bad results with cone 10 reduction in gas kiln’s. The clear overglaze crawls away from the underglaze or slip in some cases. In almost all cases the blue in the underglaze is fluxed and blurs the image. I’m getting acceptable pieces in maybe one out three firings. Anyone no a solution? BTW I’ve tried both black slips and black underglazes. Again both work when fired in oxidation.

  • Thank you so much for sharing your technique! Will add it to my ceramics “technique toolbox”.

  • Re: using commercial underglazes…short answer is yes, they may work. I teach in two community studios using purchased underglaze and firing to cone 6 in electric kilns.

    If fired to cone 6 without glaze, some underglazes are essentially colored clay slip and maintain a dry surface; others are engobes which flux and begin to develop a sheen. When glazed, some colors don’t move at all while others bleed like the blue in Steven’s work.

    Make some simple test tiles. Play with the width, depth, and direction of the incised lines. Apply your underglazes, use Steven’s removal method, and then fire using your own glazes. Nothing replaces your own testing.

    By the way, if you’re a student in a community studio, consult with your instructor first. Commercial underglazes are expensive, and the recovery system for the scraped off underglaze requires careful work. You should also use your own rib since I suspect this method may wear the edge in a way that may ruin the rib for smoothing or shaping clay.

  • Subscriber T.

    I have the same question as above, could you use an underglaze colour or should you add underglaze to slip to give colour

  • Lindsay P.

    Also works well with just oxides and water…especially on porous clay; it will soak it up and can add a nice ‘antiqued’ or ‘watercolor’ look depending on how much you wipe away.

    If anything…don’t be afraid to try whatever!

  • Lindsay P.

    Sweet! have done similar technique with layering/swirling together underglaze colors in bisquware with incised lines, and then wiping away…adds a nice effect on coil pots that are left coiled (as opposed to blended coils) when you add an underglaze color(s) and wipe away leaving color in between coils.

  • Kelley B.

    Would this not work with underglazes too?

  • Barbara M W.

    Great to read as I have been plagued with a lot of sanding back and then the subsequent glaze not getting into and grooves inadvertently caused by this sanding, dust, airbubbles??, so i will be definitely trying this method. Reusing the slip is quite a savings as cobalt prices continue skyward.

  • Subscriber T.

    hi, is there an issue of copyright in regard to the smurfs? I liked all the designs and the ‘cloud’ style on the smurf pot was way cool too.

  • Beautiful, beautiful and restful ware. Nicely done. I will try it as well, so thank you for sharing the ideas.

  • thank you, something new to try. the running of the faint blue clor is wonderful. almost gives the pieces a water color feel. thank you for explaining the process so clearly, as well as answering all the questions raised.

  • Great process, pots, glazes, surface and subject matter!

    *note to editor: traditional Korean inlay process is known as “sanggam” in Korean.


  • Beautiful, beautiful, beautiful. Very restful ware. Nicely done. I will try it myself, so thank you for sharing the idea.

  • Thanks for the response to the work and process. I thought I would chime in and respond to a few of the comments. This method works for what I need it to do, and it may not work for everyone, but it is always great to have people trying new things that may improve it. This process evolved because I felt it gave me more detail, cut down dust and sanding, and allowed me to reuse the leftover slip.

    Decals-I usually fire to cone 018. It’s pretty simple, just soak the decal in water to remove the paper, and then slide it onto the piece. You want to rub out any air bubbles with a rubber rib.

    Lowfire glaze-I’ve never tried it but I would imagine it should work.

    Unfired slip-It is a pretty thin layer so it doesn’t crack too much. but it definitely can’t be too thick or it may crack. You can add calcined kaolin to the slip to reduce shrinkage.

    Colorants-It sounds like a lot of colorants, but it’s what i use and it seems to work for me. I like the colors. I think you could definitely use your clay body slip with colorants added.

    Running-The slip runs because the glaze is running and pulls the color with it. I actually want it to run which is why it looks that way. I don’t have much trouble cleaning off the surface with a sponge, there is sometimes a very thin layer but it burns out. I also find this process to be easier for me and not as complicated as it sounds.

    *Lastly, on the topic of the word “Mishima”. I personally do not refer to this process as “Mishima” and did not label it as such in my text (it was added by the editor). I just call it “inlay”. Inlay (an english word) was popularized by Korean potters and was perfected during the Koryo dynasty (935-1392). The term Mishima came from the town of Mishima, Japan in the 17th century as a reference to inlayed Korean pots and their similarities to an ancient calendar in a shrine there. The town of Mishima isn’t even known for pottery at all. Here is a link for more info:

    Thanks again everyone.


  • I think it’s certainly worth a try, but I will just mix the oxides with slip made out of my porcelain clay body. Since porcelain only needs to be bisqued to cone 010 I don’t see a problem with adding the slip after the piece is bisqued and I don’t see any problem with using a low fire glaze and firing to 04-06.

  • Benjamin C.

    this is great! i’m going to try this today!! Thanks so much!

  • I love the mix of very traditional motifs with contemporary or non-traditional images, i.e., ancient Asian looking tree with North American birds, and Smurfs in the blue one! I love it!

    Oh, yeah, the technique is a great idea, too. 😀

  • Richard L W.

    There some excellent books available on this subject in English from Korea and the UK.

    Handbook of Korean Art
    White Porcelain and Punch’ong ware

    Handbook of Korean Art
    Earthenware and Celadon

    Korean Culture Series
    Korean Ceramics by. Kang Kyung-sook
    Published in English by The Korea Foundation

    I am presnetly doing this kind of work in my home studio as my series project in inlay of ceramic vessels in the Koryo Dynasty period of Korea 12th to 13th century. I have to make my own tools for insicing. I am using 50% B-mix and 50% Sonora white cone ten clay for throwing my vessels. I am using Southern Ice cone ten white poreclaiun slip for the inlay and black mason stain underglaze.
    I have already a tested cone ten Koryo Celadon glaze for my works at present. I did extenssive reseach on this subject before attempting it first hand, some of my pieces didn’t come out well but do show signs of an emerging inlay with more practise and with a lot of patients and I will hopefully have some to photographs later in the summer.

    Happy Potting

  • Also, another question:
    For the black slip, it seems an enormous amount of oxides (16% total) to the base slip if you add them all together. Alternatively, is it meant to be read as being additions to make separately ? For instance do you mean 4% of cobalt oxide or 4% of manganese oxide or 6% iron oxide or 2% chrome oxide or is it 4% plus 4% plus 6% plus 2% ?

  • I’ts always great to see new techniques.I feel that this one may have more problems than the more conventional way of applying slip .It will possibly be easier to trap air in the slip lines creating an air buble that will throw the slip off at top tempature creating a small patch of slip on the surface of the glaze. Because you add another process ie cleaning the work after the slip has been scraped back you are adding more time to the making process as well as adding another problem keeping the work clean of the slip.Cloured slips are very hard to get off the surface of the work piticulary ones with cobalt. If you look at the photo of the pot you will notice that the slip has run which means that either the pot was fired to high or the slip has to much oxide in it or perhaps not enough clay. Its all about a crisp clean look I feel this is going to be hard to acheive using this process.

  • you say in your text that you inlay with a cobalt porcelain slip, but the recipe you give for your white slip base is rather complicated. Do you mean that your porcelain body is actually made of the same recipe ? Would it be possible to just use the same porcelain as in the body or would it possibly flake off because that is the usual problem with a slip applied after bisque firing instead of at the leather hard stage.

  • Janet W.

    So the glaze is applied over the green (non-fired) slip? I guess that works ’cause the layer of slip is so thin…. I’ll have to try it!

  • Stephen,
    Can this mishima technique work with low fire glaze?

  • Christine W.

    I would like to know how to do the decals. Is there an instructions for that? Thanks for the bisque before slip idea. I am going to try the metal rib technique. I do lots of texture and have used a greeny to remove the slip. The rib looks like it might work better.

  • Shona C.

    I enjoy your daily information it is exciting to open the computer and there is my ceramic mail. I have used a sort of mishima with coloured glazes inlayed and scraped or wiped back and then covered with a clear glaze, the colours seem brighter and more intense.
    shona clarkson
    new Zealand

  • I started using this technique back in the late 80’s, except I was using calcined (pre-fired) kaolin in my slip recipe to prevent shrinking. I did a lot of inlay this way, applying the slip to carved bisque ware.

  • Janet T.

    Ha! How wonderful! All your words have taoght me HOW to do it! And, so many IF’s! It means, MUCH THINKING for me! Thank you, everyone!

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