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Greenbarn Potter's Supply Ltd.

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Normal Hours of Operation
Storefront is currently OPEN to the public, as of Jun16, 2021. See our COVID statement.

Mo-Fr 8:30-5PM, closed Sat, Sun and long weekends.

Next closure for stat holiday is for Christmas Break, closed on Friday, Dec 24 until Jan 3. We will re-open on Jan 4th.





Ordering Information


Plainsman Products


Low Temperature Clays

Medium Temperature Clays

High Temperature Clays


Other Clays

Native Clays

Casting Slips


Dry Materials



Encapsulated Stains


Low Fire Glazes

Medium Fire Glazes

Liquid Brights


Spectrum 500 Underglazes

Crysanthos Underglazes

Spectrum RAC Underglaze Pens

Underglaze Tools

Amaco Velvet Underglazes


Enamelling Supplies

Enamelling Tools



Potter's Wheels

Slab Rollers

Hand Extruders



Banding Wheels

Air Brushes



Throwing Tools

Trimming, Turning, Cutting Tools

Wood/Bamboo Tools

Wire and Wood Tools


Decorating Tools

Glazing Tools

Ribs & Scrapers

Ribbon/Wire Tools


Knives, Needle Tools, Cutters

Sculpture Tools

Tool Kits



Miscellaneous Accesories


Cork Pads

Oil Lamp Accessories

Dispenser Pumps

Teapot Handles

Bisque Tiles


Western Canada's largest distributor of pottery materials and supplies. Clays, raw materials, tools, wheels, kilns, slabrollers, books & much more.

Our continuing goal is to supply artists, potters and crafts people with great quality products, knowledge and customer service. Our staff is familiar with all the items we stock and can help you through the selection and ordering process. We will also see that your order is shipped according to your directions, or put together for pick up at our retail store in Surrey, BC.

BC Flooding and Road Closure Update - Nov 2021

Hi everyone,

In the wake of BC's recent flooding we would like to update you on our current supply issues. We are currently out of stock on several popular clays, and we are anxiously waiting for trucks containing Plainsman Clay. Due to the highway closures, the additional flooding, and the continued rainfall, we are unable to guarantee when the trucks can get through, or when our stock will arrive. While we can't make the stock appear, hopefully we can at least save you a trip, so please consider giving us a call to check our stock level before you drive to the shop.

If we are out of your favorite clay, maybe we can suggest the next “closest” clay so that you can continue your studio work. Alternatively, if you live on the eastern side of the road closures, you can also call Plainsman Clays in Edmonton, or Ceramics Canada in the Calgary area. Both of these suppliers carry Plainsman Clays, and although your freight costs might be prohibitively high from Alberta, they are another option to explore.

Thank you,

Craig Charlesworth & Greenbarn staff

Update: Nov 30, 2021 - Our first Plainsman truck since the Nov 15 mudslides has finally arrived!

Shimpo Wheel Promotion

Happy Holidays! If you purchase a Whisper Wheel between Dec 1 and Dec 23, 2021, Shimpo and Greenbarn will also include a FREE Shimpo Stool

Or, with your purchase of a new Shimpo VL Lite wheel, Greenbarn will provide 2 boxes of free clay (up to a value of $100).

VL Whisper Wheel, at $2139 + stool

RK Whisper Wheel, at $1969 + stool

VL Lite Wheel, at $1239 + clay

Talc Update - Oct 2021

Hi Everyone,

Due to the recent decision by Natural Minerals to discontinue supplying C-98 talc to the ceramics industry, unfortunately, we can no longer fill current and upcoming orders of this talc product. This will particularly impact clay manufacturers of low temp, white casting slips and low fire, white pugged clays. Many suppliers have already been in development, adjusting their recipes in order to make new low temperature, talc free clay bodies as replacements. This is a big adjustment and it may take some time to finalize those new products.

In the meantime, this link will take you to a "work in progress" page by Tony Hansen. Both clay and glaze recipes are being tested, as new clay recipes need an appropriate glaze to fit them well. Please note that these recipes are evolving and improving, and that you are responsible for your own testing.


My understanding is that another Talc brand will still be available. However, these other brands are not suitable for casting clay recipes. The good news is that they will work for your glaze recipes. We are passing this information along to support our community, and I hope that this is helpful for your studios while we all adjust.

Thank you, and wishing you well, From all of us at Greenbarn.

Technical Tips Blog

Glaze is bubbling with an encapsulated stain? It needs Zircon.

These two pieces are fired at cone 6. The base transparent glaze is the same (G2926B Plainsman transparent). The amount of encapsulated red stain is the same (11% Mason 6021 Dark Red). But two things are different. Number 1: 2% zircon has been added to the upper glaze. The stain manufacturers recommend this, saying that it makes for brighter color. However that is not what we see here. What we do see is the particles of unmelting zircon are acting as seed and collection points for the bubbles (the larger ones produced are escaping). Number 2: The firing schedule. The top one has been fired to approach cone 6 and 100F/hr, held for five minutes at 2200F (cone 6 as verified in our kiln by cones), dropped quickly to 2100F and held for 30 minutes.

Context: Mason 6021 Red Stain, G2926B, Firing Schedule, Encapsulated Stain, Cone 6 Drop-and-Soak Firing Schedule

Wednesday 24th November 2021

G2934 with pinholes on three cone 6 clay bodies

Three pottery mugs, two having glaze pinholes

This was a fast firing. The glaze is G2934, a silky matte. But that does not mean it is pinhole-prone, it has good melt mobility. The clay on the right is Plainsman Coffee Clay. It contains 10% raw umber, that generates plenty of gases during firing. The centre one is Plainsman M390, not normally difficult to fire defect-free. The left one, M332, should be the worst, but is the best! What is needed to fire these without pinholes? The drop-and-hold and slow-cool C6DHSC firing schedule. It is extra effort to program your kiln controller, but well worth it. If you don't have a kiln controller then by a little experimentation you can develop a switching pattern to produce the same effect.

Context: G2934, Plainsman Cone 6 Slow Cool (Reactive glazes), Pinholing

Tuesday 23rd November 2021

Was that batch of frit 3195 really bad?

After a customer experienced blistering with a transparent glaze on a terra cotta body, suspicion was raised that the batch of frit of bad. Ferro even admitted there was an issue. But we decided to test, sampling about 20 of the 50 lb bags and combining that to make these tests. Upper left is a GLFL test, if compares the melt flow of an old batch of frit 3195 with the questioned one, fired at 1750F. Although the questioned batch does run a little more, a more important difference is in the bubble development (look closer), perhaps there is some fluorine contamination. A GBMF test compares the two samples on the bottom left (10 gram balls melt downward onto a sample tile). Again, the questioned batch is melting and bubbling a little more. We made two glazes: Cone 6 GA6-B (top right) contains 20% of the frit (the left one uses an old frit batch). The cone 05 G1916QL1 glaze (bottom right, it contains 60% of the frit) uses the questioned frit and works well on both the white and red bodies. So, although it might not be working for some, we determined that the frit is OK! Although it is possible that only certain bags of the batch were bad, that seems unlikely given the way frits are made, all bags in a batch should be the same.

Context: Ferro Frit 3195

Thursday 18th November 2021

A cone 10R iron crystal glaze using only Ravenscrag Slip and Iron

Two mugs with iron crystal glazes

Ravenscrag Slip, by itself, produces a silky transparent glaze at cone 10R. It is an excellent base to which to add colorants and modifiers. This is a simple addition of 10% iron oxide (Ravenscrag Slip already contains 2% iron, making about 12% total Fe2O3). It produces a stunning crystalline fired surface on these two porcelains. We can call this a "Beyond-Tenmoku" (crystals happen because of more iron or a slow cooling rate than a Tenmoku). The 12% iron dissolves in the glaze melt during firing, but during cooling in the kiln, the extra 2% precipitates out to produce these surfaces. The iron also acts as a flux in reduction firing, greatly increasing melt fluidity. Take that last statement seriously: The iron is a flux, the glaze will melt much more. So just adding iron oxide to a glossy transparent will wreck your kiln shelves when it runs down off the ware. Ravenscrag Slip does not melt-to-glossy, it has just enough feldspar to fire to a durable surface, making it a more stable host for the iron addition.

Context: GR10-L, Iron-Red high temperature reduction fired glaze, FeO (iron oxide) is a very powerful flux, Same high-iron glaze. One crystallizes and the other does not. Why?, Ravenscrag web site

Thursday 18th November 2021

A step to prevent cracking clay mug handles

Drying cracks are opportunistic. They will initiate inside sharp acute angles. The sharper the angle the greater the chance of crack. By doing this procedure after trimming you will deny a crack a place to start. Of course even drying is still important, the water content of a handle should now be allowed to get ahead of that of the main body of the mug at any time. In the pictures on the right, two tools are being used to compress and round the angle at which the handle meets the wall of the mug.

Context: One way to avoid drying cracks on handle-joins of engobed mugs, Drying Crack

Monday 15th November 2021

An original container bag of ceramic rutile

This bag is very small, this material is very dense and heavy. The primary use of this material is obvious: For making welding rods. However notice the bag bottom is marked "Ceramic Rutile" (with a batch number). Why would a product intended for making welding rods be used in ceramics? The answer is very interesting.

Context: Ceramic Rutile

Wednesday 10th November 2021

An ordinary white mug: More difficult to make than you think!

This is M340S with G2934 matte white outside and G2926B glossy white inside. Consider what can go wrong. White matte glazes tend to crawl. No wait - they love to crawl! This would happen on every single mug unless I add CMC gum to make it a base coat to adhere well to the bisque (the tin oxide version is worse than zircopax). The clay has granular manganese added to produce the speck, if accidentally over-fired, even half a cone, it will bloat. And the clay body: The outer glaze is ugly on dark-burning clays. And it is drab on porcelains. It does not even look good on this same body if the speckle is not there. Another difficulty: Controlling the degree of matteness. I blend in about 20% of the glossy, otherwise it would fire too matte. And the firing schedule: PLC6DS - its drop-and-hold step is critical, without it the surface would be full of pinholes. Another problem: If the kiln is heavily loaded and cools slower than the programmed ramp-down, the surface will be too matte. Finally, glaze thickness: If it is too thin it will look washed out and ugly. Too thick it will bubble and look pasty.

Context: G2934, Wedging manganese speckle into a cone 6 buff stoneware, Matte Glaze

Tuesday 9th November 2021

The titanium/stain mechanism at cone 10R

An eye-popping red variegated cone 10R mug

These are porcelain and stoneware mugs. The glaze is G2571D (based on the fritted G2571B version of G2571A). This project started with calculations to source boron from a frit (instead of Gerstley Borate), MgO from talc and a frit (instead of dolomite). These moves enabled eliminating raw silica from the recipe. This produced a finer silky texture and better melt fluidity (for hosting colors). Adding rutile and zircopax produced a great bamboo. But what about variegating using titanium instead of rutile (it contains no iron so colors should be brighter)? Look what happens with this red stain! The titanium has done it's job even a little too well (creating a slightly more abrasive surface). Cobalt and titanium also worked. Imagine if other stains would produce dramatic results like this, each with the amount of titanium tuned to it!

Context: Titanium Dioxide, G2571A cone 10R silky matte recipe development project, The cone 10R Titanium/Stain Variegation Mechanism

Saturday 6th November 2021

Mason stains in the G2934 matte base glaze at cone 6

Glazed porcelain tiles showing the range of color possible with stains

Stains can work surprisingly well in matte base glazes like G2934. But they perform differently in a matte host glaze. The glass is less transparent and so varying thicknesses do not produce as much variation in tint. Notice how low many of the stain percentages are here, yet most of the colors are still bright. A good reason to minimize stain concentration is to avoid leaching. We tested 6600, 6350, 6300, 6021 and 6404 overnight in lemon juice, they passed without any visible changes. It is known that MgO mattes, like this one, are less prone to acid attack that CaO mattes. A down-side to the MgO-matte-mechanism is that chrome-tin stains do not work (e.g. 6006), high CaO content is needed in the host glaze to develop the color. The inclusion stains 6021 and 6027 work very well in this base. As do the 6450 yellow and 6364 blue. And the 6600 produces an incredible gunmetal black. The 6385 is an error, it should be purple (that being said, do not use it, it is ugly in this base). The degree-of-matteness can be tuned by blending in some G2926B glossy base.

Context: Mason 6021 Red Stain, G2934, Mason 6027 Stain, Stain 6201, Stain 6134, Stain 6100, Stain 6006, Stain 6020, Stain 6666, Mason 6600 Black Stain, Stain 6500, Stains Mason, Dipping Glaze, Ceramic Stain, Base Glaze

Wednesday 3rd November 2021

Mason stains in the G2926B base glaze at cone 6

19 glazed porcelain tiles showcasing Mason stain colors

This glaze, G2926B, is our main glossy base recipe. Stains are a much better choice for coloring it than raw metal oxides. Other than the great colors they produce here, there are a number of things worth noticing. Stains are potent colorants, the percentages needed are normally much less than metal oxides. Staining a transparent glaze produces a transparent color, it is more intense where the glaze layer is thicker, this is often desirable in highlighting contours and designs. If you add an opacifier, like zircopax, the color will be less intense, producing a pastel shade the more you add. The chrome-tin maroon 6006 does not develop well in this base (alternatives are G2916F or G1214M). The 6020 manganese alumina pink is also not developing here (it is a body stain). Caution is required with inclusion stains (like #6021), the bubbling here is not likely because it is over fired (it is rated to cone 8), adding 1-2% zircopax normally fixes this issue.

Context: Mason 6021 Red Stain, Stains Mason, G2926B, Concentrate on One Good Glaze, Stain 6404, Stain 6385, Stain 6450, Stain 6364, Stain 6300, Stain 6100, Frit VO 6134, Stain 6201, Stain 6134, Stain 6500, Stain 6006, Stain 6666, Mason 6600 Black Stain, Mason 6027 Stain, Base Glaze, Ceramic Stain, Colorant

Wednesday 3rd November 2021

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Greenbarn Potter's Supply Ltd., 9548 - 192nd Street, SURREY, BC V4N 3R9
Phone: 604-888-3411, FAX: 604-888-4247, Email: sales@greenbarn.com