Monday, June 15, 2015

Introducing Crack Pot crack filler!

Over the past few years, The Ceramic Shop has taken on the task of developing innovative new products for the pottery world under our in-house brand name ‘Mr. Mark’. Because our company got its start due to this sort of innovation with Mark’s development of the ever-popular Hydro-Bat, we’ve always considered product development to be a part of The Ceramic Shop’s DNA. In 2012, we introduced Mr. Mark’s Wax On and Wax Off; 2013 saw the introduction of our popular Ware Repair. We may have just topped ourselves with our most recent product, though – we’re very excited to tell you all about our brand-new Crack Pots! The following post will give you a little bit of background of the product, as well as detailed instructions on how to use it and what kind of results you can expect.

Crack Pot is a crack filler that you can actually fire and glaze. We came up with the idea after receiving call upon call inquiring if our Ware Repair (which we tout as a greenware or bisque glue) could be used to fill cracks. While Ware Repair is an awesome product, it can’t really be used for that – but we were confident that we could formulate something that could meet the needs of our customers. We got to work testing, and firing, and glazing, and re-firing – our head tech, Rachel, worked VERY hard to get this product just right! In the end, we found that the best way to make a reliable product was to offer several different versions, so Crack Pot is available in different firing ranges, AND different colors!

We currently make Crack Pot in four different firing colors – white, red, brown, and buff – and in two different firing ranges – low- and high-fire. This means if you work with low-fire white clay in your classroom, you may want to try our lowfire white Crack Pot; if you work with a cone 6 red clay, such as Standard 308 Brooklyn Red, you’ll want to use our high-fire red Crack Pot.

Part 1: Application

Crack Pot works on wares that are green OR bisque; however, the product works best on pots that have already been bisque fired -- one of the applications we thought potters might find useful is an S-crack filler. To prepare to fill a crack in one of your pots, we suggest assembling the following materials:

-- Crack Pot crack filler
-- Pot to be repaired
-- Small bowl of water
-- Small sponge
-- Small sculpting tool (we like this one!)

Open your jar of Crack Pot, and using your sculpting tool, scoop some out. You will see that it has a putty-like consistency; simply work it into your pot's cracked area. Once you have filled the crack sufficiently, use your small sponge and bowl of water to smooth the application. We suggest smoothing with a damp, not soaking wet, sponge. This is also a good time to clean off your sculpting tool. 

Part 2: Drying/Firing:

After you complete applying Crack Pot to your soon-to-be-saved pot, let it dry completely before moving on to the next step. Crack Pot is a versatile product; if you apply it to bisqueware, you may opt to simply glaze right over it once it is dry. However, we do recommend re-bisquing your pot, simply because your glazed results will be more consistent if you are able to do that. 

 Above, our buff Crack Pot was added to a bisqued tile (center), re-bisqued, and glazed 
with The Ceramic Shop's Golden Tan and fired to Cone 6.

The reason for this is basic clay science -- by firing Crack Pot before glazing it, you will make the material have the same level of absorbency as the rest of your bisqued clay, and therefore glaze will behave in a more consistent way across both your crack-filled section, and the rest of your piece. However, we understand that not everyone has the time and space to re-bisque their work, so we do want to let you know that yes, glaze can work on unfired Crack Pot. However, please note that your results may not be quite as seamless as the example above:

Above, our brown Crack Pot crack filler (center), filling a crack in a bisqued tile, and glazed without an intermediate bisque firing. Non-bisqued Crack Pot does absorb glaze, just not with the same consistency as bisqued Crack Pot.

If you are able to bisque firing your Crack Pot after applying, there is an additional advantage: You can sand your piece's surface before glazing, which can really refine the formerly-broken area. 

Part 3: You're done!

That's right -- using Crack Pot is VERY easy. Just a couple of steps, really! If you have further questions about this product, or anythign else in the Mr. mark line, don't hesitate to get in touch. We're happy to help. Just send us an email at, or give our shop a call at 215-427-9665. 

Tuesday, January 20, 2015

Axner Colored Porcelain

We just recently started carrying Axner's new colored porcelain samplers here at The Ceramic Shop, and already we are in love. These 5-lb. blocks of clay come in a wide variety of colors -- 14 in total! -- and they can easily be fired to cone 6. 

A porce of many colors

If you've ever attempted to tint your own porcelain, you probably know how immediately rewarding it can be -- but you also probably know how difficult it can be to repeat specific results if you've gone the route of just folding in some stains with your already-mixed porcelain. These sampler packs, though, are bright, color-soaked, consistent batches -- which is a great quality if you're a production potter looking to add just a subtle detail of color to your work, or if you're a jewelry artist who wants to achieve the same colorful outcome with each firing. 

When these sampler packs showed up in our shop, I was impressed with the packaging -- they all come in a resealable plastic container, so you know each block of clay will stay workable for a long time, and it's basically ready-made for long-term studio storage. I know in my own studio, I have all of these weird little deli containers labeled with different clay types that I use for 'detailing', which means adding little botanical-looking flourishes to my forms, so I am definitely looking forward to adding these to my own lineup.

We've had a few questions about the finish of these porcelains -- the chips shown above show what the clays look like bare (top left corner of each sample), and then clear glazed (lower right corner of each sample). As you can see, they are sharp both glazed and unglazed. The colors are bright enough to rival polymer clay, so if you are a Sculpey or Fimo enthusiast and are looking for a more durable, less expensive, and cleaner-firing material, you might really enjoy working with this product.

If you are interested in our Axner cone 6 colored porcelains, you can click here to check out all of our offerings!

Tuesday, December 2, 2014

The Ceramic Shop's Holiday Gift Guide

Hey! It's December, which means it's holiday season! On my end, the only seasonal flavor I've experienced thus far has been a few 'accidental' listenings of Mariah Carey's classic, "All I Want for Christmas is You.' That's about to change, though, as I present to you The Ceramic Shop's Holiday Gift Guide!

All I want for Christmas is THIS MUG.

The potter in your life can be, in turns, both easy and difficult to shop for. I've broken down our holiday guide by prices -- $25 and under, $100 and under, 'Fancy', and 'SUPER FANCY' to cover all of your bases, from your workplace Secret Santa who happens to be a potter, to your spouse/child/favorite human. I also have a list of stocking stuffers at the end of the post, which I built with a few of the other potters on our staff. As always, we welcome YOUR suggestions, too! If you're a potter, and you've ever received a particularly thoughtful gift, we would love to hear about it.

I'll open with the obvious -- the Gift Certificate. We carry these in virtually any amount, and you can order them online very easily. We just send you a PDF of the certificate and you can print it out before you go to your next holiday party! 

$25 and under

This is a good price range in which to purchase those cool tools that the ceramic artist might not think to purchase for themselves -- heck, they may not even know that some of this stuff is out there! 

Seger's Pottery Tools are just, well, SO NICE. These silky-smooth wooden implements all feature beautiful grains and innovative designs that are just awesome to use on the wheel. One of these tiny tools will really make your potter pal feel like they are being treated. 

In our brick-and-mortar storefront in Philly, we keep a well-stocked jar of underglaze pencils at our front desk. At least once a day, we have an incredulous customer see them, grab a handful, and proclaim 'I've been looking everywhere for these!' One of the great things about this gift is that the pencils work at a wide variety of temperatures, so if you're not sure if the potter in your life works with low-fire or mid-range clays and glazes, you will be covered by this gift! Great for the practical -- signing work -- to the decorative, pretty much any potter will find a fun use for these. Grab a few different colors!

One of our favorite, sassiest companies out there is Dirty Girl Tools. They make a wide variety of tools that are great for both wheel-throwers and hand builders, and most of them clock in under $25. Well-made and well-thought, these tools are also hilarious. From their 'foot fetish' and 'lip service' ribs intended for wheel finishing, to their 'spanker' series that works great for slab work, these tools -- which, by the way, are all designed by potters -- are a great way to inject some humor into your holiday shopping.

Handbuilders will love love love this gridded canvas -- with this, cutting accurate slabs is a breeze. Because this is just fabric, it can be rolled up and carried right to the studio! 

How about the nicest slip applicator on the market? Xiem's 3-oz. applicator comes with a variety of tips for maximum versatility. This silicone bulb fits comfortably in the hand and can be very tightly controlled, which is great for the serious slip decorator.

$100 and under

If you have a friend who is a wheel-thrower, you might ask them to see if they have a VersaBat system-- because if they do not, ohhhh man, does that make a great gift! This is a bat that fits on to any standard wheel, and has interchangeable inserts that can pop in and pop out for production. You know how round bats take up a ton of space on work shelves? These square inserts pop out of the plastic bat, making storage easy. You also have option to purchase the system with either Hydro-Stone or Medex bats.

The Ceramic Shop's own uWedge work mat is great for anyone working on the wheel or in handbuilding -- and it's a particularly nice gift for the artist working out of a home studio, as it allows them to transforms any stable surface into a wedging area. At $36, this is a reasonably-priced gift that still leaves room in your budget for some extras.

Because I work at the Ceramic Shop, I've been able to slowly add to my ever-growing arsenal of Hydro-Bat hump molds, and it's pretty much been the best thing to happen to my studio practice. I do it all -- I throw on a wheel, I handbuild, I make tiny stuff, I make large stuff -- and these molds are by far the most versatile tools I have in my space. You can use them on a wheel, of course -- they all come with attached grommets for easy fixing to a wheel head -- but you definitely don't have to do that. In fact, I largely just use them on their own, as hump molds. I roll out a slab, slam it over the mold, cut out a cool irregular edge, and with that I am able to produce several large platters each week with VERY little hassle. At any rate, these molds are a great gift for anyone who makes functional work, regardless of their preference for handbuilding or wheel-throwing.


Around this time of year, we get approached by a lot of parents and spouses looking for good 'starter' wheels or kilns for their loved ones. This usually presumes someone will be working out of a home studio, so here are some good pottery wheel choices: 

I have a Shimpo VL Lite wheel and I LOVE IT. Like any Shimpo product, it's reliable and works incredibly well, but one of the things I really love about it is mentioned in its name -- it's a fairly lightweight piece of equipment. You can throw a pretty decent amount of clay on it, yet it's still light enough to carry around -- or, in my case, carry by yourself. You will find the price of this wheel to be on the less expensive end of pottery wheels, because it is a more lightweight piece of equipment -- but honestly, for most potters (and especially for beginner potters!), that's really all they will need. Also note that we can do free shipping on these wheels within the continental US!

Another popular 'starter wheel' is the Artista. This is a tabletop wheel, meaning it's a bit smaller than the typical pottery wheel -- so you can set it up pretty much anywhere! Like the VL Lite, this wheel also ships for free within the continental US. This wheel can be as simple or as fancy as you want it to be -- add-ons include a foot pedal and a set of legs.

Another thoughtful gift for the wheel fanatic is the classic Giffin Grip. This allows for nearly-instantaneous centering on the wheel for trimming your pots, and it really great for trimming off-center or distorted vessels. This is the kind of tool that studios may have as a shared item, so it's particularly awesome when you have one of your own. 

For the ceramic artist who has the studio space to accommodate this, our North Star Ultimate Extruder Package is sure to be a very welcome addition. This is a 4" extruder made by a company that specializes in extruders and slab rollers, and it comes with a pile of dies for endless project possibilities. For installation, this can be drilled into a wall stud or a support beam.


OK. This section is kind of filled with the most awesome stuff you could get for the potter in your life -- namely, high-end equipment. Maybe I'm influenced by all of these seasonal commercials where people are giving cars as gifts; for the potter who has the space, there is -- of course! -- one very solid, very awesome gift:

A serious kiln. 

So, if someone special in your life has been hinting at a kiln, and you are awesome enough to buy that for them, there's a few things you should know. In the first place, you'll need to know the space that the kiln will be going into -- gotta make sure it will fit through the doorway, and everything! -- and you will also need to know the VOLTAGE and PHASING of said space. You definitely want to have the correct specs on this before you order any kiln. By now, you're probably getting the idea that kilns are custom-built, and yes, that's the case -- as such, they usually take about four weeks to fabricate. While this may mean you won't get to physically pass off someone a kiln in time for the actual holiday season, you can just wrap up a card with an image of your purchased kiln and you'll be a true Holiday Hero. 

Now, because a high-end kiln is such a particular thing, I do have to suggest giving us a call at 215-427-9665. One of our knowledgeable sales staff members will be happy to help you choose the right kiln for your epic surprise. We'll discuss different size options, controller options, and shape options, with a line of questioning tailored to the artist's work. We help customers select the perfect kiln on a daily basis, so if you are considering this for a gift, don't hesitate to give us a call!

This category also contains some items that don't require the same degree of customization -- provided your gift recipient has the space for the items I've listed below, you don't need to know any special specs to purchase them!

You'll often hear potters drool over the awesomeness of Brent wheels. Indeed, they are strong, sturdy workhorses that perform wonderfully and last for years and years. One of the most popular models is the strong and silent type, the Brent B Pottery Wheel. Able to handle 150 lbs of clay -- which is a LOT -- this wheel is kind of like an awesome new car -- complete with a 10-year warranty. We do carry several Brent wheel models, though, so if you look through them and are unsure which one might be right, please don't hesitate to give us a call, and we will be happy to help! Again, our number is 215-427-9665.

Much like a Brent wheel, a Brent slab roller is also quite the coveted studio equipment. While our slab rollers come in a variety of sizes, I have always loved the Brent SR-20, which allows you to roll out slabs with a healthy 20" width. This makes everything from large-scale slab building to mass production of tiny tiles a breeze, and the overall unit is so well-built and sturdy that is can be used as a work surface on its own. Like any large piece of equipment, we suggest taking the specs listed on the product page seriously, and ensuring that this will fit in the intended space.


Finally, here's a list of some items that make really great stocking stuffers for the potter in your life. Tiny but powerful, these small items are sure to be appreciated and used in the studio! We know that, because they were chosen by the potters on our staff. 

MKM wooden rollers!
Xiem's awesome retractable scoring tool!
Rubber ribs!
This awesome finishing sponge!
Bat pins!
Catalyst mini-blades!
Waterproof notebooks, great for the glaze room!
This classic wash brush!
This mini clay-gun extruder!

Again, we would love to hear about any gift suggestions that YOU might have! In the meantime, happy holidays!

Tuesday, October 21, 2014

Talc Talk

Hey, it's Tuesday, and what could usher in the new-ish week better than an expose on one of our popular glaze-room chemicals, TALC?

We do not sell talc in rock form. SORRY.

I decided to write about talc because during our recent back-to-school crush of business, we received one question pretty consistently throughout the busy school ordering season. One of our most popular clays for classrooms is Standard's low-fire White 105 (and its groggy version, 105G). Customers who have not used the clay before are sometimes surprised to see that in its wet form, it's grey -- NOT white, as it appears when it gets fired. Now, early on in any ceramics training, you sort of learn that unfired colors are often quite different from fired colors, but clays tend to be a little more close on that front than, say, glazes. 

Standard's low-fire white 105. 
It fires white, we promise!

Well, the grey color that you see in unfired 'white' clays is due to the addition of talc, or magnesium silicate, to the claybody. Talc can appear either grey or white, depending on where it's mined -- plenty is mined here in the states, where grey talc is quite common (although white talc, as seen in the image below, is also mined here). That color is a result of trapped carbon, much of which burns off in firing.

Left, Texas talc; right, Montana talc. Image courtesy

Talc is an interesting material that can perform a variety of functions within clays and glazes, particularly when used for different things at different firings. That's a pretty vague description of a material, for sure, but it does serve a very specific function in low-fire claybodies: it acts as a flux, which means it aids in the melting of other materials in the claybody, leading to a more vitrified final product. This is, of course, an important factor for low-fire ceramics -- after all, you don't want to have a permanently-porous body for low-fire functional wares, right? Adding talc to a claybody, then, can force it to vitrify a bit more than it would without the additive.

But what is talc, really, and how did it come to be a ceramics staple? 

You've probably heard of soapstone -- heck, maybe you even have a knick-knack or two that has been carved out of the stuff. Soapstone's more technical name is steatite, and it can be found in many, many places throughout the world -- as evidenced by those aforementioned knick-knacks being fairly ubiquitous, right?

The Ceramic Shop is based in Philly, though, and this corner of the world has a very interesting relationship with steatite and ceramics. I'm not even talking about an historic relationship here -- more like PREHISTORIC. Yes, steatite artifacts and steatite-tempered ceramics are a very important part of the prehistoric archaeological record in the NE United States -- and that presence speaks to a more widespread technology that, in a mind-blowing turn, we still use today.

Pennsylvania and the surrounding areas were home to indigenous groups that go so far back, archaeologists can't even identify them as belonging to any specific Native American groups -- but needless to say, they were indeed ancestors of more easily-identifiable groups we see in this area at a later date. And on that note, when I say these groups went far back, I mean like 8,000 or 9,000 years ago. People living in this area, at that time, are generally referred to as Paleo-Indians. Their technology, which we see in the archaeological record, was a lot of worked stone and some ceramics here and there. Of course they worked in many other materials, but given the moist, seasonal, acidic conditions of the northeast, many organic remains (such as wood and leather) have simply decayed over time. Not so for our archaeological inorganics, however -- that's stone and fired clay.

Beginning in what archaeologists call the 'Transitional Period' - about 3900 years ago - steatite was used to make stone bowls by these people, and those stone bowls had a few things going for them. In the first place, soapstone is very soft -- the softest, easiest-to-carve stone there is, really - so working it was much easier than trying to make a bowl out of, say, magnetite (or some other very hard stone). In the second place, soapstone bowls had this wonderful quality of not just cracking and failing immediately when they were placed in direct heat, such as an open fire. This made the bowls wonderful vessels for cooking.

This is a pretty typical, well-preserved steatite, or soapstone, bowl. 
It could take the heat. Ohhh, it could take the heat.

At this time -- thousands of years ago -- you have to keep in mind that ceramic technology in this part of the world was fairly limited. Anything that was formed and fired was earthenware, with a low tolerance for everything. This pottery cracked and broke very easily due to the difficulty that ancient potters had in getting their open-air pit-firings as hot as they 'should' be for the clay they were using. You know how pottery in bisque form seems more fragile than fully-vitrified wares? At any rate, somewhere along the road these two materials came together -- pulverized talc, when added to a claybody, imparted some if its heat-handling properties to these ancient vessels while also acting as a powerful flux, resulting in more vitrified -- and heartier wares! Archaeologists aren't exactly sure of the where and when this took place, but you can almost picture it: thousands of years ago, and area of craft production is set up. Some people are making pottery, some might be carving, that kind of thing. Some of that super-soft soapstone dust, which might just be a byproduct of carving a soapstone bowl, winds up in someone's clay, either accidentally or intentionally -- local ancients were known to add all kinds of tempers to their clay. At any rate, maybe after firing, that soapstone-tempered bowl stood out as being slightly more durable, and the addition of that material was thus introduced into the ceramic technology.

So, bringing this little history lesson full-circle, it's amazing how ancient technology can still really be seen informing contemporary products today! Interested in more information on archaeology of Pennsylvania? Check out the great blog This Week in Pennsylvania Archaeology. 

Friday, September 19, 2014

We just mesh well.

We are always happy to answer customers' questions about these raw materials; we know that chemical knowledge in the ceramic realm is daunting in its scope, and there is a LOT of information out there. Because of this, we get a lot of phone calls! Within all of those phone calls, though, there are a handful of questions that keep popping up, and this blog is a great place to begin addressing our most frequent inquiries. Have an inquiry yourself? Leave a comment, and I'll be happy to answer!

Inches. Centimeters. Microns. 

...mesh size?...

While all of these terms are units of measure that can be particularly useful to the ceramic enthusiast, only one -- mesh size -- comes across as somewhat ambiguous, as experience in raw materials consultation has taught us. Here, I explain what mesh size is -- and, more importantly, how you can start to consider it when you have option for purchasing the same material in different mesh sizes for your clay and glaze fabrication.

Mesh size is sort of like the thread count of the pottery world -- and beyond. This is a useful macro-level measurement in the fields of geology, soil science, archaeology, and more. That's right -- this is a standardized unit of measure that is utilized in many earth-science based fields, so you can push your glasses a little further up your nose and give a nod to your newfound earth-y science-y cohorts.

Taking a cue from one of those sciences, let's look at the classic geological soil size chart. This chart explains the difference in relative sizes between three categorizations of sediments -- sand, silt, and clay. Sand is the largest particle out of the three; silt is the middle child; and finally, tiny, little clay particles are the smallest.

So the graphic above lays out the technical size range of each of these important particles -- but if you're out in 'the real world' -- and by 'real world', I simply mean a world in which you don't have immediate access to, say, a microscope -- how can you tell what size particles you are dealing with? How do you separate sand from silt from clay if you are doing a project that involves mining and levigating your own clay? On my end, I've worked extensively as a field archaeologist, and I've often been called upon to do trenchside soil analysis, which means I have pretty basic equipment to work with to determine the relative particle-size makeup of any given deposit.

So what do I use?


Oh man, do I love shaking some dirt in a stack of mesh screens. Basically, in the graphic above, uppermost mesh size is your largest mesh size, with the largest-sized openings through which particles can pass. Anything larger than that stays in the tray, and when you look over at it, you know roughly how much dirt didn't pass through the 10-mesh -- meaning its particle size is larger than that. This continues down the line, with increasingly finer particles distributing through increasingly finer mesh sizes. The thing is, though, as scale of measure is not entirely intuitive. For instance, what does '10 mesh' ACTUALLY mean, size-wise, for the newbie?

Perhaps if you've purchased raw materials before, you've noticed certain chemicals come with a number attached -- say, 'Silica 325' or 'SMS 200' (SMS is the brand name for Stone Mountain Silica). Those end-numbers generally refer to a mesh size -- and this is important -- the larger the number, the smaller the particle! So Silica 325 has passed through a 325-mesh screen, which consists of particles that are smaller than 0.044 mm, while a (larger-sized) 200-mesh screen passes particles smaller than 0.074 mm. Those numbers are so tiny that both of these types of silica appear exactly the same if you place them side-by-side with the naked eye; both will present as extremely fine white powder. However, although these differences are literally quite slight in most applications, understanding relative mesh sizes, and how different sizes of materials might affect your clays and glazes differently is an important corner of the physicality of ceramics. 

And with that, I'm really starting to veer into ranty, too-technical territory -- so, to sum it all up, I've compiled a neat little list of mesh size references that you are likely to come across while shopping for raw ceramic materials, as well as the typical application of each mesh size.

20 mesh -- These larger-sized particles -- just under 1 mm -- are considered coarse for the ceramics world. You will likely see this size in association with coarse grogs. This mesh size is too large to be attached to any fine powdered pulverized materials. To give you an idea as to what 20-mesh feels like, playground sand is a pretty good visual. This is generally the roughest stuff you can (commercially) add to your claybody, so if you are new to clay formulation and want something smooth for the wheel, I'd recommend a smaller mesh size (but larger mesh-size number). 20-mesh grog is a great additive for large-scale sculptural works -- it will give your claybody a great, rough skeleton, and often contributes to a beautiful surface texture, as well, when used in large enough quantities.

35 (or 40) mesh -- Still on the 'larger' size as far as ceramic-industry particles are concerned, 35-mesh is often seen in association with medium grog. If you are looking for a gritty (but not TOO gritty) additive for your throwing claybody -- one that isn't so rough that it will chop up your hands -- I'd recommend this. This mesh size, as a grog, will also serve sculptural claybodies well.

80 mesh -- Perhaps you've seen this as a suggested mesh size to use when mixing glazes. 'Sieve twice through 80-mesh (or higher)" is typically seen on dry glaze mixes. That size is usually sufficient for breaking down the clumped-together materials in a glaze, but for recipes containing commercial colorants such as Mason Stains, I usually recommend using a smaller sieve, such as a 100-mesh. When I worked as a studio tech, my 80-mesh test sieve was one of my go-to items. It fits right in the top of a deli container and is the perfect size for small test batches of, say, 200 grams.

200 mesh -- This is where clay additives and glaze additives start to overlap, in general. This is a mesh size that results in a fine powder -- baby-powder consistency, really -- 

200-mesh is also the standard mesh size of fine grog. I mention this because people frequently order fine grog -- which pretty much looks and feels like a very fine powder -- when they actually want the toothier, larger medium grog. Fine grog is just that -- fiiiiiiiiine. And, for certain applications, it still largely works the same way. This pulverized refractory material lends strength and durability to your pieces, but given its powdered form, it's not the best choice for, say, large-scaled sculpture or wheelthrowing. It does add great strength to fine claybodies without detracting from detailed-working qualities, though. 

325 mesh -- This is the smallest/highest mesh size that you will see on ceramic products, for the most part. There are some 400-mesh products on the market, but 325 -- that's pret-ty small. 

So, if mesh sizes like '200' and '325' are so small -- small enough that by handling or looking at them, people cannot tell the difference -- what's the main difference between the two? How, specifically, can we observe them actually behaving differently as glaze or clay additives? There are a few different thoughts on this. In terms of adding, say, silica to a claybody, having a variety of different particle sizes in the super-tiny range can actually cut back a bit on shrinkage. So, if you're working with a high-shrinkage claybody -- say, a porcelain you are mixing yourself -- and you're having trouble with glaze fit or any other number of issues that can arise from a clay moving and shrinking a lot, sometimes mixing in a silica content of varied grain size -- such as 200 and 325-mesh powders -- can help that a bit. As far as glaze formulation is concerned, smaller particles stay in suspension longer, so most glaze-mixers prefer Siilica 325 over the (slightly) larger, (slightly) heavier SMS 200. 

These explanations, of course, are the greatly-abbreviated versions, and the staff at The Ceramic Shop always encourages further research (for ourselves, as well!). Hopefully this will provide you with a good starting point for understanding the correlation between mesh size, particle size, and practical application. Questions? Ask away in comments!

In the Philadelphia area (and beyond!), The Ceramic Shop has really filled a niche of supplying raw ceramic materials to studio potters, university classrooms, and independent artists alike. We pretty much sell it all, in dry form, by the pound. So whether you are just learning how to make and test your own glazes, or you're a seasoned pro, we have a VERY stocked warehouse that has pretty much everything you need.

Wednesday, September 10, 2014

NEW Electric Wood Ash Glazes!

As many of you know, we have a few different lines of glazes that we produce here at The Ceramic Shop. Our longest-running (and most extensive) series is our Cone 6 Pro Series, which was designed to mimic the look for reduction-fired glazes in oxidation, or electric kiln, formulas. The artists here at the company love and use the glazes, and they're popular with customers, too. Still, every now and again we encounter the typical potter's material issue -- some chemical source closes, or changes, or some product that we order just starts acting...different. Over time, this can make it necessary for us to alter the glaze formulas in order to make them better.

Well, our head tech Rachel has certainly been busy over the past few months. In addition to all of the other exciting projects that she has in the pipeline, she managed to reformulate two of our favorite glazes -- Electric Wood Ash and Electric Wood Ash Green. We like these glazes so much because they REALLY look like they've been reduction-fired, with cool, variegated surfaces that mimic the wild drips of wood ash glazes. And now, we're actually adding two NEW wood ash-style glazes to our Cone 6 pro Series offerings, too -- the deep Electric Wood Ash Brown, and the wild-textured Electric Wood Ash Blue. Check 'em out!

Electric Wood Ash Brown - NEW!

Electric Wood Ash Blue - NEW!

Each tile above is made of white stoneware -- Standard 240, to be exact. The upper right half of each tile features one dip into a glaze bath, and the lower left corner shows you two dips. These glazes can do alright on claybodies with a bit of a color, but most of our tests emerged looking just a little too dark or muddled. It's a light, iron-free body that really allows the variegated surface to develop and shine, so keep that in mind if you decide to try out these glazes. And how about our reformulated Electric Wood Ash (Classic) and Electric Wood Ash Green? I'd suggest the same for those, as well -- and here, for your viewing pleasure, are some close-up samples:

Electric Wood Ash (Classic) - reformulated!

Electric Wood Ash Green -- reformulated!

So there you have it - some new and exciting surfaces from The Ceramic Shop! If you have used any of our Cone 6 Professional glazes in your studio or classroom, we'd love to see your results! Follow us on FaceBook or email images of your awesome work to and we'll be happy to share them.

Friday, August 22, 2014

Can I get a witness?

Here at The Ceramic Shop, we receive calls on a daily basis from customers who have a very wide variety of firing issues. Below, a few examples:

"My glazes don't look right."

"One shelf of my work is bisqued, but one barely looks fired at all."

"The colors burned out of my decals."

And so on. We're always happy to help you troubleshoot -- particularly when it comes to the tricky world of firing issues! -- but when we get these questions, regardless of the source of the woes being clays, glazes, decals, or something else entirely, we usually start with the same question:

"What do your witness cones look like?"

More often than not, the voice on the other end of the phone line goes silent, before confessing that no, there weren't any witness cones in the firing. And with that, we can offer a few suggestions, but our true ability to troubleshoot is hobbled by this oversight. We wind up telling customers the same thing: Try the same firing again, this time with witness cones -- THEN, we might be able to tell you more. 

 Sorry, man. 
I just need more than you can give.

With the proliferation of digitally-operated kilns, it's very easy to rely on what seems to be a 'high-tech' set-up to gauge the overall atmosphere inside of your kiln. And hey, we've all done witness-cone-free firings ourselves! We know how that goes -- you load up your kiln with the same bisque configuration that you've done 30 times before and just let the digital program run or the sitter cone drop. And honestly, most of the time, that works just fine -- but it's not a great practice. Because when something does go wrong -- and as a kiln is a piece of equipment with finite capabilities, at some point, it will -- pinpointing exactly what your issue may be will be that much more convoluted. Keeping witness cones in all of your firings can also point to problems as they develop -- issues that you might not notice until they become, well, bad. Here's an example:

Say you have a kiln with a digital controller. The kiln has four elements, and they're all brand-new. You have nothing to worry about, right? Those elements will last through a great many firings! So you bisque and glaze your work using the pre-set programs on your kiln, and everything looks fine. Your work is properly bisqued and your glazes are coming out with similar results from the top of the kiln to the bottom. Why bother taking the extra step to place a witness cone on each shelf, right?

Then one day, you bisque a piece for a friend. Let's say this friend isn't the most talented sculptor; let's say they made something a little on the heavy side. You let it dry, you set a cautionary pre-heat on your kiln, but still, when you press that 'start' button, your fingers are crossed.

Two days later, you open the kiln to a ceramic massacre. Little bits of (now-fired) sherds are just everywhere; aside from the central explosion, you can see clay has been flung far and wide in your kiln, with several little chunks becoming embedded in your elements. Yikes. You call your friend and break the news through gritted teeth, and then you get to work cleaning your kiln. You sweep up the busted pieces, and then you thoroughly vacuum everything -- floor, elements, all of it. Maybe you cry for a minute. Once the mess is cleaned, though, you do your best to forget it.

A few more firings happen. Everything seems fine.

Finally, breakdown occurs. You open a glaze firing, and three out of your four shelves look fine. The fourth, however, is just an underfired, chalky mess. How could this happen? Your elements are practically new!! Is this just a one-time firing hiccup, or is there a larger underlying problem, like a busted relay or a faulty control panel? Oh, if only you had a way to just know!

If you had been placing cones in your kiln all along, you probably would have noticed the cone closest to the (now-busted) element appearing less melted with each subsequent firing. This would have been your first clue about the nature of the issue -- clearly, you had an element that was weakening. In this case, maybe a little fragment of your friend's long-ago busted pottery went unnoticed, nestled against that element, causing a hot spot to develop with each subsequent firing until it eventually led to the failure of the element. 

Granted, this is a pretty specific scenario, but the funny thing is, many of the cases we encounter here at The Ceramic Shop are. And while that doesn't necessarily mean that all kiln issues are totally avoidable, using witness cones can give you one giant clue as to what, exactly, needs tweaking on your kiln. In our firings, we like to use Orton's self-supporting cones -- they stand up on their own, so they are very easy to just pop on each shelf of your kiln. 

If you do have any questions about your kiln, or firings of any kind, we're happy to answer them! Give us a call at 215-427-9665, and one of our talented techs will be happy to chat. You can also email any technical questions to myself at, or send them to our head tech Rachel at