The use of plaster molds and mass production techniques allowed for the efficient production of ceramics, making it a popular choice for commercial ceramic production. However, slip casting as it is known today developed during the Industrial Revolution in Europe in the 18th and 19th centuries. The technique was also popular in China, where it was used to create porcelain pieces with intricate designs. The history of slip casting can be traced back to ancient civilizations such as the Egyptians, Greeks, and Romans, who used the technique to create pottery, figurines, and other decorative objects. The process involves pouring a liquid clay mixture, called slip, into a mold, allowing the slip to solidify, and then removing the mold to reveal the desired shape. Slip casting is a popular technique used in the ceramics industry to produce complex shapes and high-quality ceramic products. What is the definition of slip casting in ceramics?.Why use slip casting instead of another technique?.Invariably, whatever one my choose or decide to call 'the main mold' to make additional molds from, a harder plaster is generally warranted as this will yield a more durable mold for reproducing many other molds. Kind of like a mother having children, that are replicas of herself. Additionally I learned, during my formal education, the term, (if my recollection remains strong) mother mold as the mold from which the other duplicate molds are made. Palestine didn't offer too much urethane or latex, so that is possibly a more recent defining.) My thinking (am I wrong?) was that he was implying that a mother mold is also referred to as a case mold. In the text description's following page he goes on to state '.That the molds were evidently made from a ' mother mold' or ' case mold'.'. The example (a pictured entry) is of two identical fired clay molds (described), '.indicating that they were taken from one master mold'. However, in the book's index ' mother mold' is tabbed to an example (pg.4) and also referred to 'see case molds'. In Frith's book he defines a case mold as, '.Simply put, a case mold is a mold from which to make other molds.' which is as Lucille stated. that is probably worth the price of the book alone. Additionally I would have to say that as much as I've used the included USG Cement and Plaster Volume/Mixing Calculator through the years. I also have Frith's 'Mold Making for Ceramics', and heartily recommend it for those desiring information on moldmaking. Been out of touch with the terminology for too many years. you are absolutely correct Lucille, possibly.

If you get the book used look for those two calculators in the book condition descriptions. This book also contains the United States Gypsum Cement and Plaster Volume and Mix Guide, as well as The Frith Shrinkage Compensating Calculator enclosed in an envelope on the interior cover. I recommend a very good book on mold making. The term I think you are referring to is 'case mold' from which plaster production molds are cast.

I hesitate to do this but- the term 'mother mold' applies more to the urethane/latex mold making processes where the flexible molds are 'cradled' in a harder outer shell for support. Softer plasters (casting molds) have greater porosity and suck the moisture from the slip much faster allowing the shell of the casting to set up at a much quicker rate. As it is a harder plaster, if it is used for casting slip, because of its density, it will take much longer for the 'shell' of the slip to set up. To maintain the same size (allowing for shrinkage) of the finished pieces the mother mold is never used for production. I havent experimented with this in the slip casting phase, but im going to try making some molds within a precast 'sleeve' and see if the harder cast effects the way it interacts with the slip.Ī harder casting plaster (ie Hydrocal) is generally used to make the 'mother mold' from which the production molds (softer casting plaster) are made. I noticed by accident that if you put a piece of bone dry plaster into the plaster of a newly cast mold (when its still liquid), it sucked the water out of the general mixture and made it rock hard. I am still learning how best to make a mold that lasts. Glad to hear that molds can last that long too.

Slip cast moulds