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What people have said about Digitalfire- What a great site! Such a wealth of information. The thing I
appreciate most about the site is the orderly and thoughtful and thought
through approach to glazing. We are learning and earning potters, learning
the craft and acquiring some income from it as we grow, working with cone 6
clays and glazes. I've been visiting your site frequently recently because
we are starting to mix our own glazes, and we wanted to be able to
incorporate the textures, surfaces and colors of our choosing, not hit or
miss due to trying untold numbers of blind recipes. I've found that even a
glaze that I've seen on someone else's work, using the same glaze mix on my
work, does not guarantee the same result in my kiln, due to clay
differences, surely, but also how my kiln fires, what temps it reaches, what
timing, etc. So we want be able to work out glazes that look and feel the
way that we like, in our firing environment, on our clays.
- Your website has been very helpful to me over the past several years. I refer fellow potters to it constantly. Your G1214Z matte glaze formed the basis for the glaze used on my tea bowls.
- I have visited your site many times. We have the largest department in new england at the moment. I invited students to visit the school library to access your site directly for all its wisdom! You do far more good than you realize, fellow mud-diver.
- I would love to take a trip inside of your brain. I am sure that it would be a fantastic light show.
- I just got the Magic of Fire Reference from IMC. Good stuff in there. Have you seen it?
- After perusing your site for some time, I am really getting the sense of what a valuable resource it is. Thank you for it.
- I am so fascinated by your site I have trouble to leave it!
- I've read it cover to cover (and some sections two or three times) and I wish more than ever that I had read it before the eighteen months of mixing and testing that I've done.
- So far your site has been a blessing in that I don't feel I have to go anywhere else to get my information, you have it all (at least as far as I can see now) right here in one place. I am new to glaze formulation but not to ceramics. Recently I have had a crazing problem with a certain clay body I am using and as of today I feel confident I can solve it using information on your website. It is I who want to thank you for making such a clear and concise information depository that can be used by all, especially those new to glaze chemistry.
- I have thoroughly enjoyed the articles on your web site.
What people have said about Insight-Live- I think you have done a great job in developing the on-line version. It is very easy to use. We meet once a month to discuss any glaze problems, test glazes in teams, and I do a presentation on an aspect of glaze chemistry. One day, I said something technical and one of the member's jaw dropped and she said "Hey, I just realized I understood what you said". It was a proud moment.
- First of all, thank you SOOOO MUCH for all that you do for the pottery community. This site is such a wealth of information and the work and time you put into maintaining and updating it astounds me.
- I love all the tips and insight live is a lot of fun as well as being an amazing tool. Thanks
- Thank you for all your hard work in making this website for potters to use. We share it with everyone who comes to our store to better help answer their tougher clay questions or get them that extra education they're looking for. It's an indispensable resource.
- Tony - thank you so much! The information that you directed me is better than I could have imagined. I it has helped me learn more about how to drive a glaze formula design toward outcome objectives.
- This site is an incredible resource and I just want to thank you for it. It fills in so many gaps from my studio art ceramics education and has made me more confident in the pieces I sell. I reference it almost weekly and have recommended it to so many other potters. The ceramics world is better off learning and applying this wisdom and I'm so happy to see someone teach so technically and seriously about the material.
Culturally, there is a casualness in the pottery world (whether in community studios or school art rooms) that is borderline negligent in some ceramic circles and I just really appreciate when I see someone pursuing excellence and technical mastery of the material. Because it really matters!
- You are brilliant .. You have provided so much info that is great. I have been a full time potter for 44 years and am still learning. Thank you so much for your generosity in sending this very pertinent information to me. It certainly has me thinking I should sign on to Digital Fire. Thanks again.
- Absolutely love the insight-live web app.
- I must say you have so so much good information and with examples that it is nothing less than outstanding. I've added another year to my account. Thank you!
- First, thank you for your site. I am approaching the subject from a more technical side of things rather than decorative or functional pottery but I have found the knowledge you share to be some of the most practical and useful information I have seen anywhere.
| Please stop bashing Plainsman, the goal is only to secure Digitalfire I will send practical posts like these (from thousands I maintain). No ads or tracking. The first email will provide one-click unsubscribe. Signup is being email-bombed by bots. For now, please subscribe inside your insight-live.com account.
Blog
Resolution Achieved!
To make this happen, I need goodwill with Plainsman. I know you are passionate about this whole affair in the past few days. I underestimated how much (some were so passionate they have caused trauma with Plainsman staff). We must undo that. I suggest flowers. Having goodwill with the company I partnered with to make Digitalfire is so important and will make me so happy. There were misunderstandings, but these can be forgotten. Here is the biggest one: Digital Fire is not at risk and never was from Plainsman. I need goodwill and you can help me get it. Let's fill their office with hundreds of bouquets of flowers. Here are two online florists:
https://www.flowersin4hours.com/flower-delivery/medicine-hat-ab-florist.html
https://www.flowershopping.com
They are at 671 Industrial Ave SE, Medicine Hat, AB T1A 3L5
Friday 19th June 2026
Please Stop!
Please, everyone stop bashing Plainsman. I never intended that. Thier staff is suffering under attack. They are really upset. So much of this is misunderstandings.
The message that I put up that Digitalfire would shut down on June 26 because I was unable to meet the demands in the lawyer’s ultimatum is what made me fearful and started the whole thing. I was deluged with messages I couldn’t hope to answer so I created a response and pasted it in. I texted that response to Plainsman as well so they knew what I was saying. I should have stated more strongly that this is not about bashing Plainsman. I am very sorry for that. They are better positioned than any other company in North America because they have their own clay deposits, I want to work with them not against them.
Friday 19th June 2026
1988 Insight logo reimagined by Gemini
The old logo is from the late 1980s and was used to promote Desktop Insight at trade shows and to advertise it in magazines and later on the early internet. It was done in Aldus Freehand, an early competitor to Adobe Illustrator. Vector graphic illustration was revolutionary at the time. Amazingly, many artists even today do not know what vector graphics is, they are still working with "pixel pusher" apps like Photoshop.
I asked Gemini how it made this, and it said: "I started with a blank canvas of random digital noise (a chaotic grid of pixels) and gradually refined that noise over multiple steps based on your prompt and the layout of your original image. There was not need for a vector stage; the smooth transitions, glowing embers, and soft gradients are baked right into the generation process from the very beginning."
Context: Here is what digitalfire.., Digitalfire Insight
Saturday 13th June 2026
Same body, same outside glaze.
But the inside transparent glaze is different
Glazing black clay bodies stained with manganese is just about impossible with typical transparent glazes. The glaze over-fluxes the clay surface and ruins the color. Worse, if it accelerates surface maturity, the body can blister or generate LOI gases that blister the glaze. How about transparent glazes over a black engobe instead? At least the body color is not lost. But the wrong transparent glaze can do what you see here (inside left).
These mugs are a buff stoneware, Plainsman M340. A black engobe was applied by pouring the inside and dipping the outside two-thirds of the way down.
Left: A L3954F black engobe was applied inside and upper exterior at leather hard. After firing to cone 6 using the PLC6DS schedule, G2926B—which is crystal clear on M340 itself—became completely clouded over the engobe because bubbles generated during firing remained trapped in the melt.
Right: The entire mug was dipped in GA6-B. The Alberta Slip particles and the melt characteristics of GA6-B promote bubble coalescence and escape, producing an exceptionally glossy jet-black surface over the same engobe.
Monday 8th June 2026
Here is what dipping engobes can do:
Go on even. In one coat. Stay put.
When you learn to make and use engobes correctly, they make magic possible. Here I am turning a dark rustic body into a smooth white one (rear mugs) and a white body into a dark one (front). The engobes have been applied at the leather-hard stage. That is the perfect time, the engobe and body are clay bodies, designed to fit each other; they dry together and fire together creating an inseparable bond.
Handles have been applied, and they have dried to stiff leather hard. Engobe was poured in, poured out, then the mugs were pressed, lip down, into it and extracted. No dwell time was needed. This dipping engobe is DIY thixotropic (not available commercially anywhere). That means I tuned it just before use, to just the right degree of gel (enough for it to drain to the right thickness, then gel just as the last few drops fall from the rim). Honestly, these are a beauty to behold at this stage, the silky, drip-free surface is just so perfect.
Context: L3954B, How stop dripping and.., Here s how I.., Why your supplier does.., Why your supplier does..
Monday 8th June 2026
No glaze chemistry needed
At least not right away
You have 147 glaze recipes. How can you get your head around all of them? Is glaze chemistry needed? No, that's a "maybe" way in the future. Right now, you need to start organized documentation. The recipe for each. A few pictures of each fired on different clay bodies, different thicknesses. Perhaps slow and fast-cooled firing. This is what an account at Insight-live does well. What it does even better is tracking your testing. The first step is to assign each recipe a proper code number (replacing these) and write that on all test specimens and buckets. From this point on, learn. Record every observation you make about each in its notes.
Through all of this, constant use in the studio (or factory) will never stop surfacing problems (e.g. settling in the bucket, crazing, running, blistering, material issues, etc.). The seriousness of each will determine the level of attack. First, identify the mechanism of the desired fired result. If it is a base recipe plus additions of colorants, opacifiers or variegators, then check if the base of one of the other glazes has a similar surface texture and character. If so, then could the additives in the troublesome one be used with the better base? If not, then it's time to sanity check the recipe and bring out the heavy guns of at least looking at the chemistry. But in Insight-live, you only need to turn on the display of the unity formula (there is nothing else to do). Next, make sure each material in the recipe links to one in the material database (so the calculated formula is accurate). Then compare the calculated unity formula with a limit formula (often a simple sanity check, like with the recipe, quickly spots oxides that are in excess or are short.
Thursday 4th June 2026
A transparent glaze is going satin:
Is it the feldspar and kaolin substitutions?
A potter reports that a switch from G-200 feldspar to Mahavir, and EPK to Imerys kaolin, has resulted in this transparent glaze becoming more satin. Is that possible? Yes. Because this glaze is on a unity formula tipping point.
To see it, you do not need to know how to do glaze chemistry, just how to display the calculated unity formulas side-by-side. My Insight-live shows them here. The material change has little effect. But there is an anomaly: 0.29 MgO. That is magnesia matte territory. The MgO is very likely there to help bring the thermal expansion as low as possible (to avoid crazing). For people who cool their kilns relatively quickly, this fires glossy. But a material change could well affect the cooling rate needed to maintain the gloss. That being said, the potter may also be firing slower, yet attributing the mattness to the materials. Or it could be a combination of both.
This is a popular glaze, among others in the book "Mastering Glazes". In Ron Roy's circumstances, and for many others, it is glossy. But for this potter, a small change (in the recipe materials and also likely in firing) has produced this issue.
Context: MGBase3, Tipping point
Thursday 4th June 2026
Alberta Slip as a functional honey-transparent base:
The glaze I reach for again and again
Are glazes food safe just because they carry a label?
This Gemini-generated mug could conceivably exist yet carry these labels. Yet experienced ceramic technicians would immediately be suspicious. The glaze is highly fluid and heavily crystallized; both suggest low or very low Al2O3 levels (it is the key oxide that makes glazes durable). If the interior color were produced using a cadmium-containing encapsulated stain, cadmium-release testing would be essential before claiming the ware is food safe. This is clearly engineered for visual effects rather than durability. None of those characteristics prove it is unsafe, but they do mean that labels like "nontoxic" are not substitutes for actual leach testing. A glaze can be made entirely from materials classified as nontoxic and still fail to meet the durability standards expected of functional foodware.
Context: Commercial glazes on decorative.., ASTM D-4236 - Standard..
Thursday 4th June 2026
Should I glaze the outside of this mug now? No!
This bisque mug has been glazed on the inside. But the bisque has absorbed water from that glaze, and this thin-walled mug is now waterlogged as a result (except at the thicker base). It does not have the absorbency needed to build up a thick enough layer of glaze on the outside. Even if it did, the water from the two glazes would wet the bisque so much that its drying time would be greatly extended. This is a problem because the mechanism of attachment of glaze to the body is fragile and works best when the glaze dries quickly. When drying is too very slow, bubbling and cracking often occur (leading to crawling in the firing).
Context: Does bisque ware need.., Glaze thickness
Monday 1st June 2026
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