This jigger mold-making method features a hybrid plaster form of the outside profile attached to a 3D-printed clamping baseplate. Clamp-on rails enable easy setup and extraction for mold production. Here are the steps:
-Download the drawing, edit the bowl profile and size (and the template) and then 3D-print the parts (typically using PLA filament). Print two rails.
-3D-print threaded anchors and attach them to the base plate.
-Center and clamp the spacer ring onto the flat side of the base plate.
-Set the model mold on a level surface, pour plaster into it (right to the rim), place the base plate (anchors down) onto it (being sure it seats down into the spacer ring to assure centering). The plaster should overflow up the air holes in the plate. Weigh it down and leave to set.
-Remove the mold (using heat gun if needed), finish the surface of the plaster (with a metal rib or 3D-print one with curves to match the contour) and soap it in preparation for pouring a working mold.
-Clamp the rails down to the base plate (using paper clamps), place the mold on a perfectly level surface and fill with plaster.
-Fit the template to your jigger arm (more than one cycle of editing the upper section and adjusting hole placement will likely be needed, so don't print it solid right away).
You now have a working jigger mold for use on a Giffin grip. Repeat the last step as many times as needed.

It has been five years since getting and testing samples of an amazing porcelain-like, clean-burning, highly plastic middle-temperature stoneware raw material from south central Saskatchewan. It is far superior to anything we have now. But, due to mix-ups, it appeared its location had been lost! But coming here to search again has turned up new information and I am quite certain this is the site. Seeing and walking it has confirmed, contrary to the information we had, that the site is highly suitable for extraction. And, it is not the only site in the area, we are going to another that might be even better. The Whitemud clays here are quite different from those in our Ravenscrag quarry. On seeing the range and quality, I am beyond excited! There are a lot of ducks that have to be lined up to be able to actually extract from a site like this, but the location has a lot of advantages. The current economic realities will be a powerful motivator to developing Canadian clay sources.

This in on display at the visitor center of the Grasslands National Park in Val Marie, Saskatchewan. Perhaps ones like this formed part of the inspiration Luke Lindoe had when conceiving of the logo for the company he would form. To us, this area is "clay country", but to tourists it is a place to see the living prairie and also history like dinosaur fossils, the mass extinction boundary, hearth sites, tipi rings, bison drive lanes, and cellar depressions.

Many people suffer high-percentage Gerstley Borate "bucket-of-jelly" raku recipes they find online. Most of these are just transparent base recipes to which colorants are added. After years they found ways to tolerate this strange bedfellow. Now, a more normal material, Gillespie Borate, seems odd and is causing issues in the alternate reality "Ghastly Borate ecosystem". There is a better way. A frit is perfect for this application, Ferro Frit 3110 (or Fusion frit F-75). All it needs is 15% kaolin (e.g. EPK) to produce and easy-to-use recipe that is guaranteed to craze. The degree to which it crazes can be adjusted by trading off some of it for Ferro Frit 3249. We have assigned it a code number of L4264, a raku base transparent recipe. We have also catalogued some common recipes that people use and outlined the issues they have: L4264A, L4264B, L4264C, L4264D. Do you need a white? It is a simple matter of adding 10% Zircopax to this.

This is not as good as using a cup-head, but it has advantages for potters and hobbyists. These include easier mold making, only the top side needs to follow a precise contour, the bottom is just flat. And a wide range of sizes can be accommodated. It is also more convenient because the wheel head of the potters wheel does not need to be removed. And, of course, it is less expensive.

Pretty well all common traditional ceramic base glazes are made from only a dozen elements (plus oxygen). Materials decompose when glazes melt, sourcing these elements in oxide form. The kiln builds the glaze from these, it does not care what material sources what oxide (assuming, of course, that all materials do melt or dissolve completely into the melt to release those oxides). Each of these oxides contributes specific properties to the glass. So, you can look at a formula and make a good prediction of the properties of the fired glaze. And know what specific oxide to increase or decrease to move a property in a given direction (e.g. melting behavior, hardness, durability, thermal expansion, color, gloss, crystallization). And know about how they interact (affecting each other). This is powerful. And it is simpler than looking at glazes as recipes of hundreds of different materials (each sourcing multiple oxides and thus affects multiple properties).

This is part of a test hybrid case mold for a Medalta Potteries ball pitcher. The bottom plate is 3D printed and the top form is solid plaster. Recessed holes in the back of the plate enable securely inserting screws into threaded anchors embedded into the back of the plaster form. The upper plaster surface has artifacts (stair-casing remnants) from the 3D printed shell used to cast it. While these could be sanded out, we find that a flexible metal rib works much better. Even better than that is this custom 3D printed rib that I made, the edges are sharp and precise. I designed it with contours to match the belly, neck and rim of this piece. Using this, it takes minutes to smooth out the surface.

I have had a dream of being able to slip-cast jars with this type of fastener. Until this week, I did not even know what they are called or anything about their history. Now I do.

The first step was to design and 3D print a prototype. After three iterations, I found the best measurements for these bails, for use without a silicone or rubber sealing ring, to be 19.5mm vertically between the rings, a lid ring seat diameter of 79mm and a rim ring seat diameter of 87.5mm. It is going to be a challenge to create slip casting test molds to make jars out of ceramic instead of glass - the latter does not shrink out of the mold while clay has both drying and firing shrinkage. That being said, 3D printing enables quickly changing a mold design and size, reprinting in PLA and remaking a plaster mold. 3D printing also enables making holders, cutters and jigs to tool the diameters precisely at the dry stage. After that, precise firing along with monitoring of clay firing shrinkage should enable success. After that: Embossed designs cast into the flat walls.

G2917, which I mixed as a brushing glaze, is on the right. This is not sold in jars, I make my own labels as part of the demonstration that it is possible to make your own brushing glazes (ink-jetted onto regular paper, cut 62mm wide (2 7/16") and held securely on with 2 7/8" transparent packing tape). This glaze is less runny but lacks some of the floating white colouration. But that can be achieved using Alberta Slip floating blue L4655, it employs titanium instead of rutile (and relies on the rutile/iron mechanism for the blue color).

This spoon was dipped into a ceramic dipping engobe, L3954B. It contains no CMC gum, it was only flocculated using powdered Epsom salts. Without the Epsom salts, the engobe runs off, leaving only a film. But, when turned into a thixotropic slurry, it stays on the spoon in an even layer (as a gel), then hardens as it dewaters (left) and finally dries completely (right). With no cracks! It also fires to cone 03 with no cracks. Of course, if this were fired high enough, it would begin to shrink, crack, crawl, melt and then craze, ceasing to be an engobe. Of course, special low-expansion frits and additives and mixing, preparation and application techniques make enamels, which do melt, possible for metals.