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Ceramic and Porcelain Decorating Part 1

Today I would like to go over various methods that we use for decorating our ceramic and porcelain beads and jewelry items.  The types of decoration and methods used can vary greatly in the time, tools, products, and talents required to accomplish them.  They also vary in where in the production cycle they are applied to a piece.  It is this variety and choice that is one of the things I like best about creating with ceramics and porcelain. Today I will cover processes up to and including glazing, starting at the beginning of the creation for a piece.  I will try to think of all the various methods and processes that could be used to decorate it.  I want to compare the look, the difficulty, the benefits and features of each method.  Bear in mind that this reflects my opinions and they may be different from yours.

Ok lets get started we have wet clay in front of us.  We have several choices for decoration already.

Stamping: We can stamp the wet clay using a rubber stamp or a carved clay stamp or a wooden stamp or some organic object.  This is one of the easiest methods of decorating clay.  You can simply roll it out and press the stamp
Tutorial by
Sheila Lapointe
or object into the clay.  The talent required is more in the placement of the design(s) on the piece and the shape.  Of course, if you are making your own stamps there is a different talent involved there as well.  The photo on the right of a mold made by 'stamping' lace into clay illustrates the talent of placement of the decoration.  The mold is then used as a sort of reverse stamp.  The photo is linked to a tutorial on this method.  This method of decoration is pretty quick and multiples of the same design are, in general pretty easy to accomplish.  Once the piece has been stamped and has dried it can be further be further enhanced with more decorating techniques later in its process. (see below).

Carving: We can carve the clay as it begins to dry out.  Complex designs can be carved into clay using a variety of tools.  This is a relatively easy method of decoration.  The clay is not difficult to carve and it doesn't have grain to complicate things like say wood does.  Care must be taken to not allow the object to dry out too much while one is carving it or it will become more brittle and easily broken, however.  More talent is required for the carving than stamping because you are creating the design by your own hand not just transferring it into the clay surface.  Some aids to this would include tracing a pattern onto the clay with a pencil or stylus but the depth and contours of the design are created by hand using the tools.  This method does not lend itself to exact copies as it is nearly impossible even with a traced design to get the carving done exactly the same.  It also takes considerably longer and is for that reason also not really well suited for multiples.  It does provide for much more variation in the depth, contour, and texture of the design and also can result in sharper edges.  Carving can be combined with stamping to modify and enhance a stamped design as well.  The carved design can also be further enhanced with more decorating techniques later in its process.



Slip Trailing.  Slip trailing is a process where decoration is
Moriage Style Dragon
by Marsha Hedrick
created by applying liquid clay, or 'slip', to the item.  The slip can be the same color as the item or it can be colored with mineral stains prior to its application.  In many ways slip trailing is a form of sculpture.  You are creating a relief pattern by building up clay on the surface.  The Japanese used this technique over a 100 years ago to create beautiful decorative china pieces.  Some of the most well known of these are the Moriage Dragons commonly called dragonware these pieces are very popular to this day and command a high price in the antique market.  The Japanese used a cloth bag similar to a cake decorating bag to do their dragonware.  Some people today use a syringe or a squeeze bottle to apply the slip. 
Dragonfly Focal Bead
By Joan Miller


 Others such as myself and Joan Miller use brushes. This technique can be very quick or take much longer depending on the type of decoration and the style that you want to achieve.  The slip trailing can be combined with some carving to sharpen details.  Slip Trailing can be done on wet or dry clay, although most people do it on clay that is at least somewhat wet.  The talent required again depends on the complexity of the design.  Since you are applying clay to the surface only a minimal amount of transferring of design can be done as you quickly cover up what is transferred.  As you build up layers of various colors you have to be able to visualize the pattern you want to achieve and the colors. 
Wedgwood Style Bead
by Marsha Hedrick
Slip colors are very muted and pale in comparison to the colors after the piece is fired which further complicates this technique.  On the popular 'wedgwood' style pieces that I do the 'wedgwood' blue porcelain is nearly the same color as the white, being only slightly grayish.  Also the slip is not translucent as it will be when it is fired so the shadowing so commonly seen in Wedgwood type
Wedgwood Style Bead before firing
designs is not evident when you are working on the design.  These next two photos illustrate this.  On the left is the finished bead with all the delicate shading evident.  On the right is the finished but unfired bead.  Knowing how much white to apply over the blue to get white and how much will leave a slight blue tint for shadow is more dependent on experience and the talent of the artist than being able to see it when working on it.




Quimper Snuff Reproduction
by Marsha Hedrick
Underglazing: As the clay begins to dry out we can utilize underglazes, mineral oxides and stains to decorate it.  This type of decoration can be a simple color wash or a detailed complex painting.  The talent required to do a color wash lies in the ability to remove just the right amount of color or to apply a thin coating.  Detailed paintings require the ability to draw the desired design onto the surface or to keep the paint on the desired areas of a stamped or carved decoration.  Underglazing techniques can mimic watercolor paintings or can be bold opaque shapes.  For the most part the painting will appear somewhat like it will after firing, although the colors will be generally somewhat muted and it is not always obvious if you have accomplished complete coverage.  The little vessel to the right is a reproduction of an antique Quimper (pronounced Kam-pare) snuff from http://amazingporcelain.com.  It was painted using underglazes.  The original was majolica. (see below about majolica)  Again experience goes a long way in accomplishing a great result.  Underglazes can also be used with a silk screening process which does make the process of underglazing suitable for the production of the same design over and over and changes the talents and tools required for the process.  As with the other techniques so far we can further enhance these decorations later on in the process.


Terra Sigilatta is another method of decorating/finishing a clay piece before it
Terra Sigilatta pieces by
Work of our Hands Group
is fired.  This involves the 'painting' on of a very fine clay mixture known as terra sigilatta.  After it has been brushed on it is usually polished with a soft cloth.  The photo on the right is from a group in Namibia.

 Burnishing: Burnishing is another method of decorating or finishing a ceramic piece.  In burnishing the piece is rubbed with a polished stone, plastic film, metal spoon or other smooth hard object to achieve a gloss that is not as shiny as glaze but much shinier than the unburnished piece.  Burnishing compacts the outer layer of the clay organizing the platelets that make up the clay into a more uniform and compact plane and encouraging them to lay flat. (clay is made up of tiny flat slab like particles)The flat sides of the clay particles reflect more light than the edges which is one reason for the shine.  Burnishing is usually done instead of glazing and the pieces are not fired over 1000C as the platelets will start moving at that point and the burnish is lost.  Burnishing is an ancient technique and is used on most Native American type pottery.  Burnishing makes the piece somewhat more resistant to water which is one reason ancient potters used it.  The cab shown below was burnished to achieve the shine you see on it.


At this point the item is most likely ready for its first and possibly its last visit to the kiln or fire.

Hand Carved Wood Fired Cab
By Marsha Hedrick
Firing The first firing is commonly referred to as the Bisque Firing.  In some cases it may be the only firing, such as the Cab on the left or when someone decides to fire the glaze directly on greenware.  This cab is an example of a piece that was hand carved (technique #2 above) and then fired in a wood fire which was then smothered with cow dung to produce the deep black coloration.  But in most cases ceramic pieces including most porcelain, stoneware, and earthenware are fired twice.  Some people will fire their bisque to a much lower temperature than when they glaze others will do the opposite.  Firing of the bisque to a lower temperature is much more common on the porcelain and stoneware type clay bodies as these bodies vitrify when fired to maturity and are no longer porous making them more difficult to glaze. 

Glazing: After the Bisque Firing most pieces will be glazed.  Earthenware pieces (commonly called ceramic) will almost always be glazed as they remain porous and in an unglazed state they are less durable.  Some decorative earthenware pieces are decorated with paints called Bisque Stains which are basically acrylic paints and the ceramic is not glazed first.  This method is not as durable as a glazed surface and is not commonly used for beads or jewelry in my experience.  Porcelain and Stoneware on the other hand vitrify if fired to maturity and are no longer porous so they can be quite durable without glaze and can be quite beautiful as well.  Colored porcelains and rich earth color stoneware bodies are quite appealing with an unglazed matte surface. This brings us to our next decorating method Glaze.


Hand Carved and Detail Glazed Cab
By Golem Studio
Glaze can be a protective coating as well as a decorative one.  If we have decorated our piece using underglazes or mineral pigments before firing a clear glaze will prevent that somewhat fragile and thin coating of paint from wearing away.  This is particularly important on earthenware pieces.  With porcelain or stoneware the underglazes tend to fuse more strongly to the body when the piece vitrifies and they are much less prone to wear without glaze.  Nevertheless a nice clear glaze can enhance the colors, protect the painting and give us a shiny finish.  If we have carved the piece we can use colored detail glazes to color various portions of the design such as the Cab seen on the left.  Colored glazes are also available both in a translucent and opaque variety.  Some with spots or crystals that melt for a burst of color.  Applying a translucent colored glaze over our stamped or carved pieces will result in darker colors in the deep recesses and lighter colors on the raised bits greatly enhancing our design.  Some opaque colors called art glazes will create a frosted appearance in the recesses or variations of color as well.  Glaze choices are further expanded by textural glazes.  Some that look like tree bark or pebbles.  The basics of glazing are quite simple and very little talent is needed to glaze a piece.  The talent and magic of glazing comes from combining various colors and textures of glazes into appealing decorative finishes.  The right amount of a textural glaze over a shiny colored glaze can be very appealing.  Glass fragments can be incorporated into a glaze or simply applied on top of wet glaze to melt in the
Donut Pendant with Glass
By Kristie Roeder
firing.  Glass melts at a much lower temperature than the glazes and the coefficient of expansion is much different, consequently the glass fired in this manner will melt and the crack on cooling.  This can remain quite firmly attached do to the underlying glaze or in some cases it can chip off.

Majolica: One technique that deserves mentioning is majolica.  This technique is one that sort of comes out of order.  In majolica a design is painted onto an unfired glazed surface using underglazes.  This is basically backwards to the ordinary method of using underglazes.  There are a few important things to note.  With majolica a specialized glaze is used that does not run as much as most glazes.  This is what allows this method to work at all.  Glaze in general melts when fired.  Most glazes will become fluid at that point and to a certain degree they will run.  Some run a lot and you have to be careful that you don't apply too much to close to the bottom of a piece or too near a hole etc.  Also if you put them close to another glaze the colors will mingle and they will run together.  If you place an underglaze design on top of this sort of a glaze you will end up with your design being totally distorted. 

At this point the piece is ready to be fired again.  If it was originally fired to a lower temperature it should be fired to maturity at this point.  If it was fired to maturity prior to glazing it can be fired to a lower temperature in the glaze firing as long as it is fired hot enough for the glaze to mature.

After the glazing we still have options for decoration.  These options fall under the category of 'overglazes'.  Do you notice a trend here.  We have 'underglazes'  they go 'under' the glaze.  We have glazes and then we have 'overglazes' which are products that go 'over' the glaze.  Next Month I will go over those techniques

7 comments:

  1. What a wonderful and comprehensive post, Marsha.

    Sharleen

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  2. Fantastic post! Always nice to have reminders of the many techniques, well done Marsha!

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  3. I've never heard of the Majolica method and am curious about what glaze you would use to do this method. I'd love to experiment with this!

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  4. WOW!!!! Thanks for all the invaluable information in these different techniques!!!

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  5. Majolica uses a specialized glaze that is designed to not be runny. You can find these at most ceramics places. Historically a fritted underglaze was used on top of the unfired glaze. These days many people are using the detail bisque underglaze or glaze products such as Duncan Concepts or Mayco Stroke and coat for this sort of a technique. The base glaze needs to be a non runny glaze then there are a variety of options that can be used for the decoration.

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  6. So many pretty pieces and such an informative post! I really love those slip trailing pieces, beautiful!

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  7. Terrific post Marsha! Very informative~

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