This is version 10 of my Medalta ball pitcher case mold. I am still determined that a standard 3D printer with PLA filament brings complicated molds within reach of almost any potter or hobbyist willing to learn 3D design. The project has evolved to become hybrid, using both plaster and 3D prints in the final mold. Two views of the PLA prints needed to pour a plaster half-model are shown at the top.
-Plaster is poured into A.
-I attach threaded anchors to the underside of the baseplate C (using bolts through the small inner holes), they hold the plate firmly in place on the plaster half-model.
-B is a spacer, it is clamped to the underside of C (and aligned using bushings in the holes), it is only used during the model pour.
-Bottom: A is on a perfectly flat and level surface. It was filled with plaster just to the rim and then the baseplate was placed on top of it (the spacer acting to correctly position it). More plaster was added and a few minutes after this it was scraped off flush.
After hardening the spacer can be removed, the mold peeled off using a heat gun, and the plaster surface finished and soaped. The 3D render also shows one of the side rails, D. It holds in place by a flange that wraps under and locks into the holes (the last version used magnets; this approach has several advantages over that).

The 3D design of this handle mold was challenging because of the lack of a defining edge to guide cutting it, at leather hard stage, to accurately fit against the body of the bellied shape (a Medalta ball pitcher).
Center: I solved that problem by creating 2mm pipe along the path defined by the join between the handle and the spares.
Upper left: It has been 3D printed using PLA filament. The walls are only 0.8mm thick so printing is fast. The low profile means there is no bulging from the weight of the plaster. The clips and embeds are in place, ready for the plaster.
Lower left: The plaster cast mold halves (with natches and spacers glued into the embeds). I used a heat gun to remove the PLA prints cleanly (to preserve crisp corners).
Right: The halves fit together perfectly.

A kaolin shipment just came in. "UnReady Freddie" is panicking. He thinks he remembers that products made with the last shipment were lacking plasticity and the fired color was off. He is going to have to come up with different lame excuses for complaining customers this time.

"Ready Freddie" has Insight-Live and has collected years of data on incoming shipments in one searchable place. He knows what to check on each and has fired bars, in-mix tests, particle size checks, data sheets, lots of pictures, notes, etc. He also has traceability - he knows what material batch went into what product. He works with production to do material lot tracking and with purchasing to keep suppliers aware he is testing. Because Ready Freddie knows how materials vary he can compensate recipes and processes so customers see a consistent product.

UnReady Freddie has a few spreadsheets somewhere. But he is busy with other things. Who do you want in charge of product consistency (and company reputation)? Here is what to do next: Have your technician study the page "Testing a New Load of EP Kaolin" (link below). You will be hearing from him/her soon.

Are you the technician at a company producing clay bodies, glazes, and underglazes? That creates a lot of data. Are you storing it in spreadsheets? That’s like filing lab reports in a shoebox! Searching for data ends up taking longer than the test itself. And it is seldom in the format you need, it is not linked to anything else, it doesn't have the information you need. Excel was not designed for this, your lab deserves a database. Databases enable insight. Insight-live.com is the right home for all the data you collect.

Imagine all your lab data in one searchable, structured, secure system — everything hierarchical, linked and accessible. Being able to compare results across time, batches, and processes. Having a full data trail. For example, maintain master recipes of everything and track their evolution — what changed, why it changed, and how it performed. Maintaining a file system full of thousands of spreadsheets is great for burying data.

The least expensive Shimpo banding wheel right now is $155. So I 3D printed my own as a test (this marvellous idea came from Crystal Bennett). The middle section is designed to fit inside the upper. To make it heavy, turn over the upper section, fill it to the brim with plaster, then press in the middle section until the plaster comes out of the holes (then weight it down till the plaster sets). The base is hollow, so it can be filled with plaster too. A standard 17x40x12mm roller bearing (available for $5 at the time of writing), it fits tightly into the recess in the middle section (and the base stem fits tightly inside of that). The resultant turntable turns super smoothly and rotates remarkably true. This drawing is parametric, so the dimensions can be adjusted easily. The size of the bearing that it will accommodate is also adjustable.

These glazes have not just crazed or shivered, they have pulled part of the body with them. What can generate forces great enough to create failures between glaze and body like this? Differential thermal expansion. Consider:
First, the glaze is thick. Very thick. Much too thick.
Second: A strong body:glaze interface zone has developed. That's good.
Third: The body is not firing to optimal strength (it appears porous). Not necessarily bad if the glaze fits.
What to do? Apply the glaze thinner, of course. But, testing should also be done to determine whether the glaze is under compression or tension. This could be done using the EBCT test.

The clay is Plainsman 3B.
Left: Without processing, other than grinding to 42 mesh (currently the finest we can grind on a practical scale), if fired toward zero porosity it burns like this (at cone 6, 8, 9, 10 and 10R bottom to top). Of course, this material is mainly used in non-vitreous bodies at cone 6, so these are not issues. The speckle and bloating are caused by impurity iron-bearing particles and others having an LOI (they decompose and produce gases that cause the bloats).
Right: The impurity particles make up a small percentage, they can be removed in our lab by sieving to produce a natural porcelain that fully vitrifies by cone 6 (the middle bar). Only about 5% of the material was removed to produce this amazing product (we call it MNP).
Imagine what could be done if we were able to mine raw material further east, where clay quality is much better!

Reactive glazes (melt-mobile, crystallizing or heavily pigmented) are the least suitable for food surfaces because they have the potential to leach metals. Liner glazing ware is an excellent way to deal with this problem. Not only does this approach improve functionality but it can be aesthetically pleasing and practical in production.

This liner is GA6-B, a pottery glaze recipe we promote with confidence. Not only is it less likely to be leaching metals but also less likely to craze - this assures water tightness on non-vitreous bodies and eliminates any potential for bacteria growth in the cracks (especially if the body has porosity). Unfortunately, glazes that leach are also likely to stain and cutlery mark - these add more reasons why they are most often unsuitable for food surfaces.

The straightness of the dividing line is affected by both the application technique and the degree to which the two glazes bleed into each other and run. Read and watch our liner glazing step-by-step and liner glazing video for details on how to do this - it is practical for any potter or hobbyist (or even in production). And tap/click the picture above for other examples of this.

CAD software and 3D printing are a potential revolution in vessel mold-making for ceramics (3D modelling is another topic). But there are two big problems: There is no way a potter, hobbyist or even small manufacturer can afford the typical software cost. While it is true most have free or low-cost trial or hobby versions, the strings attached are deal breakers. The second problem is the complexity of learning - that can be a bigger obstacle than cost.

Until the recent price increase Fusion 360 seemed to be exactly what was needed. A great way to on-board the CAD world, using the free version and its great learning resources and best-in-class user interface. It is new and modern, a YouTube star. It is fully parametric supporting constraints and a timeline. True, it can choke on more complex drawings on consumer computers, but we don’t need to do those. But, for commercial use, it costs $680/yr. But that is cheap compared to some others! Upon discovery of the capability, the cost might be doable for you.

Here are the ones you likely cannot afford (and maybe don't want):
-OnShape runs in your browser. It focuses on collaboration for teams. Free-version drawings are public but going private costs $1500/yr!
-Rhino is usable for CAD but is polygonal and targeted at modelling. It is not fully parametric and does not have a traditional timeline (however Rhino+Grasshopper is life-changing for geeks, both for CAD and modelling). $1000 to buy but upgrading is $500+.
-Solidworks is fully parametric with editable history. But it is old, the interface shows it. It is low cost for hobby use but for commercial use it is far out of reach for individuals ($2600/yr in 2025).

Some upcoming possibilities:
-FreeCAD is becoming more viable. It is parametric, has constraints and exports and imports popular formats (but with lots of issues). Its model tree is equivalent to the Fusion 360 timeline, but more clunky and depends on careful setting of constraints. The learning curve right now puts it out of practical reach of most. But a capital injection, like Blender got, is coming.
-Shapr 3D costs $299/yr, also works on iPad (which Fusion 360 does not), and uses the Parasolid engine like OnShape and SolidWorks. But it seems to be targeted at being intuitive for conceptual modeling and quick prototyping for drawings that are finalized in other products (limited support for accurate feature placement, constraints, parametrics and boolean operations).

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.