Digital and in-Person Teaching by Jerry Bennett

Studio Potter  Winter/Spring 2019. Vol 47. No. 1. 

Beginning Your Exploration of Fiber Clay, by Jerry Bennett

Artists’ use of paper clay is relatively new in the history of ceramics. I attended the first international paper clay symposium in 2002 at the International Ceramic Studio in Kecskemet, Hungary, and then as co-leader of the second symposium ten years later. One of my major impressions from both symposia is how different artists’ interests in and use of paper clay are. Since there is such diversity in the use of paper clay, it leads to confusion for artists new to the material.  

One possible source of confusion is that when we use the term “paper clay”, we are really talking about a material composed of cellulose-based fibers, not just paper fibers. The cellulose-based fibers commonly found in paper clay are paper, cotton, linen or flax (form which linen cloth is made), and kenaf, also known as jute. Protein fibers, such as wool, and  Manufactured fibers, such as nylon or fiberglass, don’t work as well as cellulose fibers because their structure is not complex enough.   They lack the hollow  tube structure of cellulose fibers or, in the case of protein-based fibers, they decay very rapidly. Cellulose fibers allow for a capillary action when used in the clay body, improving the workability of  the clay. In reality, we should be referring to this material as fiber clay, not paper clay, to help artists understand this material. 

Speaking of materials, one of the most common questions I get asked during my workshops is about whether it’s a good idea to use dryer lint in clay. You want a source of fibers in your clay that is consistent and that you can obtain in enough quantity to meet your needs; dryer lint doesn’t meet either criterion. 

Another question I get is about using toilet paper as a source of fibers. Because toilet paper has additives to make it soft, fiber clay using toilet paper lasts only a week before it begins to break down. If you want to use toilet paper, look for toilet paper without additives, usually a very low-quality kind. Toilet papers made of recycled materials might be acceptable because they are less likely to have organic additives. 

I advise people to use newspapers to begin their work with fiber clay, first breaking the newsprint down in water to make a pulp. Use only news- print for your fiber source, not the shiny-surfaced advertising sections. 

Paper clay artists use different fibers, and combination of fibers, based on the type
of work they are making. I use a fifty-fifty mix of paper and second-cut cotton linters in porcelain to make my fiber clay. I add ninety grams (three ounces) of fibers to a twenty-five pound bag of plastic porcelain. Note that the weight of fibers is based on a dry weight. Remember that how much fiber you put into clay depends on the type of clay and what you are making.
If you are pushing the capacity of a clay such as thin porcelain, or working with complex sculptural forms, try increasing the amount of fibers, or combining fibers in this order: paper cotton, kenaf and flax. Experiment with ratios and different fibers! 

For sculptural applications, you can easily double the quantity of fibers. A mix of news- paper fibers and cotton afforded me the best balance, providing a faster way of working. 

Other fibers, such as kenaf, may be very rough, unless they are reduced to a very short fiber such as that used in papermaking. The best way to incorporate these into the clay is to purchase fibers processed for papermaking. You can buy them as sheets of paper, then break them down and incorporate them into your clay. Many of the commercial fiber clays use kenaf as part of their fiber mix. Use kenaf fibers for sculptural work, rapid-fired work, or raku. 

Abaca, also known as Manila hemp, is another fiber used for papermaking and
is a good material for mixing with clay. Abaca fibers are harvested from the bark and stem of the plant. Abaca affords a good mix of fibers, both short and long, making it an excellent addition to clay. When I
use abaca, I use about one hundred grams of fibers to twenty-five pounds of plastic clay and reserve it for sculptural work. 

The slabs I work with are tougher, more like wet leather than a slab of traditional porcelain. Porcelain has a uniform particle size, making it inherently weak and difficult to mold, and the porcelain I use is like working with toothpaste until I add the fibers. Much larger than the particles of the porcelain, the fibers act like rebar in concrete. Cotton added to the fiber mix increases the dry, greenware strength. When I make larger forms that are difficult to move into a kiln, I increase the amount of cotton fibers in my clay. 

Artists in Europe have developed one of the most interesting fiber clays: casting slip with fibers, which they use to cast very thin, translucent slabs. They start with deflocculated clay slip, add fibers, and then dry it to the point of a plastic clay for use. Often their fiber of choice is flax. Flax creates a very strong clay body and makes building very large sculptural forms possible. Some of the artists using flax make sculptural work that goes unfired. Over time, the clay surface darkens and remains very hard. 

Sources of fibers for your work can be as simple or complex as you want. The simplest source is newspaper or fibers from papermaking supply houses, such as Carriage House Paper (carriagehousepaper.com) and, in Canada, Twin Rocker Handmade Paper (twinrockerhandmadepaper.com). You could also ask printmakers or other artists using paper fibers for their sources. Experiment with fibers, sticking to supplies that are consistent—ones that will yield the same results time after time.        

Paper Clay Workshop Handout   3/31/25

Additional training: www.jerrybennett.net (under "Paper Clay")

YouTube: Jerry Bennett youtube.com/@porcelainpaperclay 

Shop for my pottery at www. www.jerrybennett.net/shop

Facebook Group: Ceramic Paper Clay

By Jerry Bennett

© Jerry Bennett 2024- this publication may be used for educational purposes if you give credit to the author.
 

I have been thinking recently about the importance of working with ceramics and how, time after time, I have been influenced by old traditional techniques in ceramics. Ironically, I have discovered significant influence in pit-firing traditions and, recently, the use of paper clay. Paper clay has many advantages for the modern clay artist, including higher pre-firing strength, reduction in warping, and increased joining capacity in wet-to-wet joints and dry-to-dry joining. Additionally, it has made many techniques available to me that I could not have thought of even a year ago. Super thin building techniques, translucent porcelain, and a swift working style are all opportunities I have experienced. Here are some of the things I have learned along the way:
 

It's essential to be safe with materials (dust, especially with silica ,as it is a significant hazard)

The method described below uses handheld power tools and ceramic production equipment. Use caution in the studio when equipment is involved. The mixer spins at a high speed, and you should always keep your hands out of the bucket when mixing clay. Follow the directions printed on the tools and read the operation manual. Wear a dust mask when mixing dry ingredients such as paper or clay. When firing paper clay in a kiln, ensure adequate ventilation to prevent breathing kiln emissions. Read all safety publications concerning the materials you use for your safety. Don’t use moldy (Black) paper clay. Test these techniques and materials before producing large amounts of work.
The Clay
You can make paper clay out of any clay you want to use. Generally speaking, the more refined the clay, the more benefit of adding paper fibers. For example, the benefits of porcelain having paper fibers are very pronounced, lesser for stoneware and almost none for earthenware. Commercially paper

clay is used to retard warping in clay, reduce the weight of clay objects, and reduce the cost of producing

clay objects by replacing part of the clay with paper fibers that cost less. Adding fibers or wood chips is a common practice in the brick-making industry.

"Paper clay," or should we call it "fiber clay": 

Paper clay is best when the fibers are equally disbursed into the clay mixture. Many commercial companies mix pug-milled clay with paper fibers. I feel this is not the optimum way to make paper clay. However, clay mixers such as Blue Bird and Soldner Clay Mixers can better mix the fibers within the clay, and a wet (slurry) mixture of clay works best. I mix bagged moist clay with additional water (1 to 2 gallons of hot water per 50 lbs.) until it is as thick as yogurt. This clay can have lumps in it for as long as it can be broken down during mixing. I use a standard five-gallon plastic bucket to make 50 lbs. of clay. After filling the bucket with about 1 ½ gallons of water, I add 25 lbs. of clay to make the bucket half full of slip, and I mix the clay very well with a paint mixer attached to a standard drill. This 3 Blade Spiral Mixing Paddle, Hercules Brand, 30", fits ½" chuck or larger, Model # HA219-03 is available at Harbor Freight Tools as item # 58335.  www.harborfreight.com

I then slowly add the second 25 lb block of clay and keep mixing the clay. Standard Clay now offers many of its clays as a dry mix.  This dry mix of clay is highly recommended for making paper clay. Remember to make only the amount of clay you expect to use in about two weeks. It is essential that the wet clay is well mixed and that all of the lumps are worked out of the clay before adding the paper fibers. Mix the clay until the mixture looks like thick yogurt or pancake batter. At this time, at your option, you can add a small amount of bleach (about one tablespoon) into the mixture to retard bacteria and reduce discoloration of the mixture. Bleach is unnecessary when using cellulose insulation or cotton and may be omitted. Next, mix the clay and paper fibers. The mixture will thicken or gel, a normal part of the process. Let the mixture sit for a short time, and mix again. The final mix should be very even in color and have a smooth texture. At this point, the mixture should be thick enough that you can remove the mixture from

the bucket to a drying bat or rack with your hands. After drying to the desired consistency, the paper clay can be stored in air-tight plastic buckets. If you use paper instead of cellulose, use the paper clay quickly, taking care not to make more than you can use in two weeks. Cellulose insulation-based paper clay can be stored for 3 to 5 weeks without spoilage. Store all paper clay in a cool, dark place. If mold forms on the surface of the clay, spray the surface with a spray bottle filled with water and a minimal amount of bleach.

Always wet fibers before adding them to the clay, or you will find it hard to mix dry fibers into the clay.  Before mixing the clay, place the fibers in a bucket and add water.  Paper, bamboo, or cotton fibers will soak up the water. 

Adding Cotton to the Clay: 

I have recently been adding cotton to clay instead of paper. Cotton, a form of cellulose, is an excellent addition to clay because it lacks starch, which forms rot and is easy to add to the wet clay mixture. I use cotton linters, which is the 2nd cutting of the cottonseed. This shorter fiber can be easily chopped. This type of cotton is sold for papermaking and is relatively inexpensive. I found an online source using Google and searched for "cotton linter" papermaking supplies. Most of the cotton is sold in sheet form and by the pound. I recently purchased ten pounds at $2.50 per pound. One of the significant advantages of cotton to clay is that the fibers are natural and not colored with printing inks or other contaminants. I have also found that cotton fibers are very stable in clay and don't rot as fast as paper cellulose. I have also found that because of the size of the fibers, I can add a lot more cotton to the clay than paper.
Although the cost of cotton fibers is much higher than that of paper, the overall benefit to the clay is excellent enough that it is well worth the additional cost of using the material.

Bamboo is a great fiber to use in clay. Bamboo, like cotton, doesn’t promote rot in the clay. I have made significant changes in my studio practice in the past year. I have moved to dry clay supplied by Standard Clay (365 porcelain), and instead of cotton, I am now using bamboo toilet paper. I use one roll of toilet paper to 50 lbs. of clay.

Paper:
All types of paper can be used for paper clay. Many people use toilet paper because it is very fine-milled and easily broken down in the mixing process. There is a perfect reason not to use this paper source. Toilet paper contains starch as a sizing material. When broken down in the clay mixture, toilet paper will

rot almost immediately. Paper clay from toilet paper will turn dark gray

and stink in about ten days. The paper clay will work fine, and when it burns out in the kiln, it will return to the clay color without a change in the fired state. Don't use paper clay that has begun to turn black. There could be a health hazard associated with the use of this material. I recommend that you use other kinds of paper which are less expensive, such as newspaper pulp. Soak the newspaper in hot water, then beat the fibers with a drill with a mixer attached.  This breaking down of the fibers will take about five minutes at high speed.   To test the fibers, take a clear glass of water and add some paper/water mixtures.  You can see through the glass of water and judge how broken-down fibers are.   If there are chunks of paper floating in the water, keep mixing until the fibers are well liberated.  Drain the water, and the fibers are ready to add to the clay.  You can dry out "patties" of the fibers for later use. However, wet fibers should always be added to the clay. Dry fibers added to wet clay will never thoroughly mix with the clay.

Amount of Paper: About 800 grams to 50 lbs. of clay is about the limit. Above this amount could be used for large hand-built forms but is not recommended for general handbuilding. Resist the impulse to put a lot of paper fibers into the clay. A small amount of fibers in relation to the amount of clay works well. Too much paper and clay will present problems in the fired state. I use porcelain; too much paper causes the clay to be very translucent, hard, and glass-like and tends to dunt (crack) in the glaze firing.  If there is too much fiber in the clay, it will begin to feel spongy and soft when you work with it.

You can use much more paper when using red earthenware or stoneware clay. After you have added the paper fibers, mix the clay with your paint mixer for several minutes. I would also recommend adding one to two tablespoons of bleach to the mixture. Ensure the mixture is even in color and all the material on [1]the bottom of the bucket is well mixed into the paper clay. The mixture should be much thicker than when you started. It is an excellent idea to let this mixture sit for about fifteen minutes and then remix it. The water in the clay will continue to soften the paper fiber and get ticker. Place this mixture on a drying bat to dry the material to a workable consistency. In my studio, I place the wet clay on a piece of cloth on a concrete floor, which dries the clay in about a day.
Storage:
Don't store the wet (slurry) clay mixture for any time. The wetter the mix, the more prone it is to rot. Store the clay in an air-tight container and put the container in a cool place. During the summer, sun or heat will rapidly cause the clay to rot. Don't store the clay in a clear container (I have made this mistake.) When working with the clay, allow all scrap materials to dry out; when you want to recycle clay, wet the clay with warm water at the last moment and mix it into the batch of new clay. When used to bond joints for hand building, paper clay slip tends to rot because it is stored in a wet slurry state. This damp slip will need the addition of bleach from time to time to prevent rotting.
 

Rotting Problems:  Store all paper clay in a cool, dark place. If mold forms on the surface of the clay, spray the surface with a spray bottle filled with water and a tiny amount of bleach. When stored in a warm place or for an extended time, paper clay will form mold on the inside of the clay. If rot forms, the clay should not be used. The paper clay can be used again by allowing the clay to dry and then putting the dry clay in water with a small amount of bleach. Add this slurry mixture to your next batch of paper clay.
People have made recommendations on Clayart, and other internet locations that adding Thymol to the clay is a way to prevent the rotting of the paper clay. I do not recommend that you add this chemical to the clay. Thymol can be absorbed through the skin and is an irritant, especially to the eyes. Read the safety information about the chemical before you use it. http://website.lineone.net/~dave.cushman/thymolsafety.html. Thymol is used by adding crystals to rubbing alcohol. A tiny amount of this alcohol (cap full) is then added to the clay mixture. Thymol has a very distinctive odor. Once added to the clay, it can't be removed. Thymol remains in dry clay that may be reprocessed and could contaminate future batches of your clay. Thymol is also an ingredient in Listerine Mouth Wash.  Use about 1/8th cup of Listerine per 50 lb. batches of clay to reduce rotting.

Commercial Paper Clay: If you purchase paper clay from your clay supplier, review the printed safety sheet available from the supplier.  Often, you will not know the material added to the clay to prevent spoilage, although they will list the chemical names.  I have elected to make paper clay rather than have these materials in contact with my skin. Remember:  Store paper clay in a dark and cool location.
Drying:

Plaster mold for a drying batt: P&S SlumpHump Mold, 14" X 14" X 2.5". Available at Axner.com (Laguna)

(Plaster Mold about $90)

Many of my students use bread racks that they get at a local store. These bread racks are about four inches high and 30' square. They are made from the same plastic that the five-gallon plastic bucket is made of and used to deliver bread to the local store without crushing it during delivery. They are made to stack on their corners without touching the bread.

I spread a cloth mat on the bottom of the rack and spread a two-inch-thick layer of paper clay on top of it. I then stack the bread racks up, and the clay can dry rapidly because of the airflow around the frames. This drying method works very well for all types of clay and is better than plaster bats. When the clay is dry to the consistency I like, I remove the cloth backing and store the clay in large plastic containers. 

Remember to store the clay in a dark, cool place. Try not to use a clear storage container. I think the dark blue buckets at Lows are better than the orange buckets from Home Depot, which let in some light.
 

Properties of paper clay:
 

You can make paper clay out of any clay body that you are currently using.
 

Paper clay increases the dry strength of the body so that moving large pieces is less of a problem. Paper in the clay "opens" up the clay body so that you can work with thicker walls for sculptural forms. Water vapor will escape the walls because of the paper; the threat of exploding walls is reduced.  Cotton or flax fibers will significantly increase the raw/dry clay strength.  Remember, the most fragile time for paper clay is when the fibers have been burned out in the bisque state. If you are going to break a pot, it probably will be in the bisque state!
 

When working on sculptural forms, you can add multi-layers of clay. These additions can be added at any point in the forming process. You can add wet-to-wet, wet-to-dry, or wet-to-bisque. (You can add wet clay to bisque and re-fire the piece.) Paper clay will withstand multiple re-dampenings to make changes in its form. Paper clay will withstand forced drying. Paper clay allows for late-stage additions to a piece; even when dry, paper clay will stick to the form and allow changes. Cutting a handle off a piece and reattaching a better handle is easy and something I always do
 

The fired results of paper clay are the same as rthose of rgular clay. 

Short paper fibers are better than long fibers. Other materials, such as nylon or fiberglass, do not add

advantages to the clay because you need cellulose-based fibers. Other fibers are hard to cut and decrease workability in the clay. Don't use glossy or colored papers in paper clay. The ink used on newsprint will not add color to the fired clay. When using newsprint for your paper source, add a tiny amount of dishwashing detergent to the water that helps break down the fibers.
 

Paper clay reduces the weight of the clay body because the paper replaces part of the clay with lighter paper fibers.

Always add a film of water to all joints in clay construction. Clay-to-clay joining will fail if you don’t first add a layer of water to the joined clay.
 

Paper clay can be used on the wheel. But, a better idea is to use regular clay on the wheel and use paper clay if you attach any hand-built additions to the form. Handles made of paper clay are less likely to crack, and the paper helps bind them to the surface.
 

Paper clay slip (Bonding Slip) is excellent for joining glue when handbuilding forms. The paper fibers in the clay increase the strength of the dry bond.

Casting slip can be an excellent source of clay for making paper clay.  Start by adding damp fibers to the slip and dry it out using the techniques listed in this paper.  You can add the fibers to the slip and then use the slip as a dipping material for any organic material. For example, try dipping rope, seed pods, twigs and branches, leaves, etc.  You can dry them out and then take some slips and stick them together or add them to pots.
 

Paper clay can be used as a repair material for cracked pots. (It's usually better to discard a broken pot and spend time making a better one!) The Clay and paper slip can be forced into the crack for repair. The paper helps to hold the patch in place and increases the repair bond.

Hint: You can repair a bisque pot. Soak the pot in water for about ten minutes. At the same time that the pot is still dripping wet, force paper clay into the crack, dense pack if you can. Don't worry about the surface; just get as much clay into the crack as possible.  Let the piece dry, then smooth the surface with a wet sponge. Bisque the pot, and if the crack is still there, repeat the process until the pot is free of the crack.  This process will fix almost anything!   I  have a student that uses this idea to make pots.  She throws the pot on a wheel, trims, and then bisques the pot to Cone 08.  Breaks the pot on the floor into small pieces and then reassembles the pot using colored slip. In all of these “repairs,” I have never seen a joint failure! 

You can build hollow armatures to support large sculptural forms very quickly. First, force dry the 

7 Jerry Bennett Pottery 2024 ã

armature and then work with soft clay on the surface.  Ensure all joints have water between them to ensure adhesion of the joint.

 

Paper clay reduces the amount of shrinkage and warping.  Tile makers would benefit from using paper 

clay to make tiles or any flat object.  The fibers in the clay, which transport moisture and keep the clay 

from moving during drying, makes drying tiles much more manageable and reduces warping.  You could even force-dry the work.

Graham Hay was one of the first paper clay artists to use dry clay to dry clay assembly.  Dry-to-Dry Assembly allows you to pre-make elements to assemble into a sculpture using paper clay and letting the parts dry out.  Make a thick paste from the same paper clay and then dip the elements into the paste where you want to attach the pieces.  Graham demonstrated this technique at the International Ceramic Center in Hungary by dipping cotton rope in paper clay slip.   He strung the rope between two trees and allowed the rope to dry completely.  Graham then cut the rope into 5" sections and then used these sections to assemble his sculpture.   By dipping the ends of the rope sections into the thick slip, he quickly attached them. He allowed the tower sections to be set briefly before adding another level.   He built a 6' tower in about 30 minutes!

Paper clay allows for a single fire: Because paper clay is tough when bone dry and absorbs about the same amount of water as bisque, there is almost no advantage to bisque pots made of paper clay.  You can use the same techniques but omit the first firing.

Paper, when added to clay in the amounts listed in this paper, will not cause damage to an electric kiln. However, increased amounts of cellulose fired in a bisque kiln quickly could cause a small amount of smoke in the kiln room. If this is a problem, reduce the amount of paper fiber in the clay or fire the kiln slower for the first 1/3 of the firing. Adequate ventilation is essential in all kiln firings. In most cases, adding pieces containing paper will not make any noticeable difference in the firing process.
 

If you have questions or comments, please contact me at jerry@jerrybennett.net

Thank You!
I would like to thank the Clay Studio in Philadelphia (www.theclaystudio.org), The International Ceramic Studio in Kecskemet, Hungary (www.icshu.org) and, Canada's Banff Center for the Arts in Alberta, Canada, for providing help and support. These valuable artist organizations have allowed me to develop this work by supplying residencies. I would also like to thank Rosette Gault, Lori Nelson and Graham Hay for their pioneering work in paper clay.

Rosette Gault http://www.paperclayart.com/ (Books and information)

Graham Hay http://www.grahamhay.com.au/paperclay.html (Excellent information)
Banff Center for the Arts http://www.banffcentre.ca/ (Great Place for a residency) 

8 Jerry Bennett Pottery 2024 ã

The Clay Studio, Philadelphia http://www.theclaystudio.org/ 

Lori Nelson- Paper Clay Forum on Facebook https://www.facebook.com/groups/1594190214237067/

Graham Hay has a wonderful listing of Paper Clay artists from around the world at:

http://www.grahamhay.com.au/paperclayartists.html

© Jerry Bennett 2024- this publication may be used for educational purposes if you give credit to the author.