Kennedy Snider
- Jan 12, 2022
- 14 min read

Intro Ceramics Guide

Updated: May 10, 2023

Week 1 - Introduction to the studio

Cleaning procedures and studio safety

Intro to hand-building techniques and wedging clay and a discussion of interests!

You’re invited to bring sketches to the next class as we talk about pottery forms, and your vision.

Week 2 - Introduction to the wheel

When you arrive to class begin by wedging up 2 balls of clay roughly the size of your fist. Maybe 1 1/2 to 2 lbs of clay.

Hand-builders are challenged to come up with their own project and may come to me for ideas or advice.

At the end of todays class, make sure to cover your work in plastic so we can trim them next week.

Week 3- trimming, and more wheel throwing

When you arrive you may want to wedge some clay for more throwing on the wheel, you may get started on this as soon as you arrive. I will begin a trimming demonstration as soon as everyone has arrived and settled in. Any work thrown last week should be trimmed today, so don’t forget!

Week 4- Handles

Many of my beginner students aim to make objects with handles, such as mugs, teapots, pitchers etc… Having pots ready to trim this week is a good idea, as freshly trimmed pots are the best dampness to attach handles.

Week 5- Lids

With a lid you can made a jar, a casserole dish, or a teapot! The lid and body should be thrown at the same time so they have a god fit.

Week 6-Spouts!

Pitchers, teapots, Gravy boats.. why wouldn’t we want something that pours. Week 7-

Week 7- Surface decoration on greenware

We will look at combining texture techniques with underglazes, and slips to create a dynamic surface.

Week 8- Glazing

We will have done a small intro already but this class will have a little more glaze info

Week 9- Free Day!!

Down to the last three weeks, it’s time to finish our favourite creations! This is probably the last wet clay day if you’d like to have it fired up to temperature (glaze fired!)

Week 10- Surface decoration on Bisque

This week is for wrapping up projects and making sure your last day isn’t rushed! Glazing takes more time than you think!

Week 11- Last Day to Glaze. Last Class!! Until next time.

About Clay

The largest source of clay formation comes from weathering of high silica, sedimentary rocks. For this reason clay deposits are often found next to river beads, lakeshores or beaches where exposure to water is high. Diagenesis is also another source of clay and occurs when minerals are so tightly compacted that they destabilize, this explains glacial formed clay deposits as they were pressurized under kilometres of ice.

Clay particles are made of alumina, silica and oxygen at a basic level. Minerals in and around the clay deposits determine the “personality” of the clay, changing the colour, the plasticity and the firing temperature. For instance, the presence of iron will darken a clay body often to a redder hue. Iron oxide is also one of the many flux components found in clay that lower the temperature needed to reach vitrification. Because different clay bodies vitrify at different temperatures different firing techniques have been developed to accommodate. Below I’ve outlined the different types of clay bodies, and some examples of their use in ceramics history.

Types of clay bodies

Earthenware - Low to mid-range firing

Earthenware is a low temperature clay body that is found all around the world. Because of its approachable low firing temperature and its abundance nearly worldwide, its presence is found throughout history as different societies found it useful for food preservation, as cookware, storage vessels, and for artistic expression. Earthenwares porous walls allow water to escape through them and therefore they need a glaze on tops to be watertight. Terracotta ( Italian for “scorched earth”) is a warm red earthenware clay body.

Stoneware - Mid-range to high fire

Stoneware comes in many different colours, textures, and can be fired to a varying range of temperatures. Many begin to vitrify around cone 6 and others can withstand the high temperatures of a cone 10. We typically use a midrange stoneware in beginner friendly pottery studios as we know they will produce work appropriate for functional wares and sculpture.

Porcelain- High-fire

Porcelain is a very fine grained, high fired white clay body originally dug and developed in China in the Eastern Han Dynasty. These clays fire around cone 9 and may go as high as cone 11. An essential part of porcelain’s make-up is kaolin clay, which aids in its plasticity, durability and translucent appearance. Porcelains introduction into European culture after the 14th century has influenced ceramics culture in the appreciation and appropriation of Chinese ceramic aesthetics.

Stages of your project

As the clay dries you’ll find it changes dramatically.

Slip- This is a clay and water slurry that is useful in a variety of ways. Slip can be cast similarly to concrete.. or melted chocolate… it is also used as a glue for adhering two pieces of clay together properly. Slip is a natural byproduct of throwing, and may be dried and wedged to be used for the next creation.

Plastic / workable- fresh out of the bag, freshly thrown or able to bend without snapping.. The clay will feel moist, look darker than it’s next stages, and is the perfect hydration level for molding, modelling, rolling flat, coiling… this is plastic!

Leather stages- This can be around the hardness of refrigerated butter to frozen butter. Two pieces of clay can be attached at this stage, if done correctly. Both pieces should be scored and slipped and water should be sparingly introduced to limit the stress of rehydrating the clay. Firmer clay is great for hand building with slabs, carving into, or standing impressions. This is the perfect stage to sign your work!

Bone Dry- Clay projects are in their most fragile state here. They’re ready for the kiln and should not be reintroduced to water or they risk cracking and dissolving back into the plastic stage. Greenware will feel room temperature to the touch when completely dry, and there is no moisture to cool it. Here it will appear the lightest in colour that it’s been so far. long as your name is on your project, It’s now ready to go into the first kiln firing! Look for the blue shelf that says “Greenware/Bisque”

Bisque- When work is completely dry and finished in its clay state, we can then move it onto the bisque shelf to be fired. This firing occurs at the cone 05 stage. This firing changes the project from clay to ceramic, making it durable enough to rehydrate with glaze, without cracking or crumbling or to store until further use. In the bisque state your project is porous. Water will not hold long in a bisque vessel before seeping through the walls. This porosity is what makes it so useful for the glazing process, as the water-based glaze is sucked into the pores and dries completely in a matter of minutes.

Glaze Firing- The glaze firing is usually the last step in producing your ceramic work. After the bisque, your work may be decorated, or glazed and then put into this glaze firing to reach its final temperature. In our studio this is around a cone 6, which allows the clay to be nearly vitrified and water-tight. Liner glazes are required on the inside of functional vessels for holding water and food in order to be food-safe however the outside of functional wares may be bare clay if that is the artistic intent.

Surface decoration and Glazing

Different glaze materials and application techniques are useful in realizing the vision you have for your work. Below I have outlined materials and the stages at which to apply.

Glaze- The glazes in our studio all melt around cone 6. They are water based concoctions of alumina, silica, fluxes (melters) and colorants such as stains or oxides. Glazes are applied in the bisque stage as the porosity of the ceramic draws the water and therefore the glaze, onto its surface. Glazes melt completely and should adhere to anything they tough in the kiln. For this reason we never glaze the bottom of a work as this would result in it fusing to the kiln shelf. Always lease enough space near the foot of your piece for the glaze to run a little. 1/4 to 1/2 inch is safe. Glaze should not be applied too thickly, as the heavier it is on a piece the further it will run down the form. Brushing or dipping two glazes on one piece often creates beautiful results, as a chemical exchange may occur between the two in the kiln. However, this should be done with caution, as double dipping can thicken the amount of glaze on the piece, or the chemical reaction may cause them to run more than they would have on their own.

Coloured Slip- Slip is a slurry of water and clay, when applied in colours that contrast the clay body of your form, they can be useful to surface design. Slips in our studio should only be applied in the leather hard stage or before. Coloured slips can be layered and carved into, and they can act to texturize a surface.

Underglaze- Underglazes can be applied in the leather hard, greenware, or bisque stage. These are colorants mixed with a painting medium for easy application. The colours remain bright in our mid-range firings but do not look exactly the same before and after firing. Often they darken and brighten although the pink is known to loose pigment. Underglazes should be applied using three solid coats in order to achieve a uniform colour. Mixing colours in encouraged. As the name suggests, the underglazes always go under, (never over) a glaze. You may want to use underglazes on their own for a matte finish, just remember they’re not technically “food-safe” unless there is a glaze over top. Clear is the most common glaze to use with these.

Stains- Stains are colorants applied most commonly over a glaze after it has dried, and before the last firing. Stains are most commonly used on white so they show up properly. Look up traditional majolica wares to see stunning ways to use them. Testing is strongly advised as they can be difficult to apply.

Wax- Waxing the bottom of your pots is a useful tool to keep the glaze from ever adhering as it will resist water, and glaze is primarily that. Despite this, always double check the bottom to make sure it is clean and clear of glaze before putting on the glaze shelf. It is worth noting that wax may be applied for a number of surface decoration techniques in any stage. It can be applied on bare clay, on underglaze, on top of glaze. Just get creative! It will burn off completely in the firing.

Glossary of terms:

Vitrification - The state in which a clay body is at its peak porosity and hardness. Clay particles have shrunken together, and are tightly packed allowing for a completely water tight vessel and often very smooth surface.

Cone- The cone which a project will fire to directly relates to the way in which we tell how how the kilns are without the need for finicky digital thermometers. A plyometric cone is essentially a stick of glaze that will slump at exactly the same temperature every time. Here we have a pack loaded for cone 10, 9, 8, and 7 (from left to right) temperature readings. We can tell that the kiln temp did not reach cone 10 due to the slumping of all but one.

Wedging- often compared to “kneading” the clay, this process is meant to expel all air bubbles from the clay as well as to align the clay platelets which will often and add plasticity to the clay. You can look up videos of “spiral” or “goats head" wedging for reference.

Wheel Terms

Throwing - Throwing is the act of using the potters wheel to create a vessel form. The etymology the word “throw” comes from the old English term “thrawan” which means to twist or turn.

Trimming- This is done in the leather hard stage, after a thrown piece has dried enough to carve into. Trimming removes excess clay, and refines the shape. This is done by reattaching a vessel upside down onto the potters wheel to work on the foot.

Centring the clay- positioning the clay directly in the middle of the wheel head so that you can throw a form. Perfectly entered clay will not wiggle side to side, but will look almost stationary while spinning. Remember to breath at this stage!

Opening the clay- Done on the wheel, only after entering is complete:

Part One: create a hole in the centre that leaves a 1/4 inch of clay at the bottom. This establishes the depth.

Part Two: after the depth is established, widen the centre opening by pulling the wall towards your body. The walls should only be opened as wide as the clay below if or it risks collapse.

Pulling up the walls- this is done while on the wheel: pinching extra clay from the bottom of the form, and lifting it up the height of the walls. This will grow the vessel taller/ bigger and will thin the walls.

Coning- Coning is one of the beginning stages of throwing occurring either after or in conjunction with entering the clay. This process involves moving the clay to resemble a cone shape, before coning down into a rounded shape again. When done properly this will help with centering, it will align clay platelets so that its at peak plasticity, and it may even pop some unwanted air bubbles.

Foot- the foot of the pot is the very bottom, where the object meets the table

Lip- the lip of a vessel is the rim, or opening. On a cup form the lip is where our mouths touch the object when we use it.

Neck- The neck of a vessel is the narrowing near the top. A vase will often have a neck, whereas a bowl form most likely will not. Narrowing the neck is done through Collaring

Shoulder- The shoulder of the pot is directly below the neck. This relates to the Belly of a pot, but the difference depends on where the visual weight is distributed… creating a belly or shoulder shape is often achieved through stretching the clay wider using one hand on the inside of the form.

Gallery- In a jar or on a lid, is a thrown or trimmed “step” or “foot-ring” that allows the lid to sit without fear of sliding off. This is especially important for teapots aw we tip the whole vessel to pour. However you never want any lid falling off and breaking, so it’s an important step not to forget.

Handbuilding

Coil- A coil is a long worm shaped piece of clay that may be wrapped around itself to create volume. Imagine a spring, or a “coiled” snake. Coils may also be added decoratively, or as handles. They’re often used to reinforce a thin joint, such as an inside corner of a “slab” object…

Slab- Slabs can be treated similarly to fabric, or even wood depending on the wetness of the clay. They are flattened pieces of clay used to create functional and sculptural objects. You can have 6 cut into squares to make a cube, or you could have one curved around a pipe to create a vase. The slab is versatile and easy to roll out with a rolling pin or on the slab roller.

Pinch Pot- a pint pot is very much what it sounds like, but should not be underestimated for its versatility. A pinch pot may be used as the base of a form, adding other hand building techniques on top. It can easily become a lid, or even a spout when you cut through the bottom. This technique involves creating a small hole 3/4 through a ball of clay, and evenly pinching the walls while rotating to flare the walls out and up. Pinching in this way can be used for decoration as the surface is mesmerizing and displays its unique handmade quality.

Tools

Ribs- rib tools are generally straight and can come in a variety of materials. Wood, Metal, and silicone are the common suspects. Ribs can help you throw, and come in many different shapes for this purpose. They’re excellent for hand building as they can smooth away fingerprints and bumps. The serrated rib is metal, and has teeth to help texturize, or score for attachments.

Wire Cutter- This tool cuts through clay easily and you will use it a lot during the plastic stage. Cutting a finished project off the wheel head is always done with a tight wire tool.

Trimming/Loop tools- Also called ribbon tools, these are metal loops that carve easily into clay. Trimming with these is best done during a firm leather hard stage, and never during a bone dry stage as it creates too much dust. This can be harmful to you and your studio mates.

Pin tool- Something pointy that is perfect for writing your name on the bottom of work! Very important. But also adding decorations and carvings, or cutting off a pesky lip on a wheel thrown object.

Health and Safety

The studio is a shared space where everyone deserves a safe and clean environment to work in. Here are some ways to keep us all healthy, and how they’re protecting us. Hazards of a pottery studio

Dealing with DUST! A ceramics practice is indisputably centered around one material above all others.. Clay. The makeup of clay is essentially Silica, and alumina, with various other minerals that depend on the type of clay used. Silica dust is a hazard in the studio if not kept to a minimum. Silica is carcinogenic and can irritate the lungs especially over l one periods of exposure (such as years working in a studio environment) Potters have kept healthy in this practice by following simple rules of dust management.

We never sweep if we can help it. - Try to wet mop first if possible! Keeping those light silica particles wet will weigh them down, and easier to clean up.

We are meticulous wipers! - Any surface in the studio will quickly accumulate dust. Wiping multiple times in the same area will help lift the dust to be rinsed down the drain.

We never dry sand or trim work - Sanding can be done with wet/dry sandpaper only under a faucet or in a bucket of water. If your work is too dry to trim without dust, its a sacrifice we must all make for the safety of the studio. Talk to an instructor about ways to finish your pot without it.

Lastly, make sure your clay doesn’t follow you home . Rinse your clothes before loading them in the washing machine, and consider an apron to stay clean! I know you don’t mind a little clay on your pants, it’s a messy activity! But make sure you’re not breathing in clay dust even once you’ve gone home.

And- if you’re extra concerned, you can always wear a dust mask or respirator.

Hazardous materials- Most hazardous in the ceramics world will thankfully be well labeled or generally kept out of reach. However, many decorative materials that are commonly used should be cautiously approached.

Please do not forget that the glaze room is essentially a chemistry lab, full of chemicals that have both safe, and unsafe uses. Please treat it with respect, and follow precautions when dealing with glaze materials. Mixing glazes or painting decoration with these materials should be done carefully and a respirator is required for dry materials. Gloves are encouraged as well for materials that can absorb into the skin.

Physical Wear and tear- Be mindful of your body while in the studio. Stretching is always encouraged throughout your studio visit and beyond. Clay is heavy, details cause you to hunch over your work, wedging is tough on the wrists… this is a physical practice!

Intro Ceramics Guide

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