Slip casting is a process that uses a form of clay that is liquid. The liquid clay gets poured into a plaster mold. As the time progresses with the slip in the mold, the plaster draws out liquid from the slip. This leaves a clay wall against the inside of the plaster mold. Once sufficient time has passed that the slip has sat in the mold and the clay wall is the desired thickness, the excess slip gets poured out of the mold. The mold is then left to dry until the clay form inside the mold releases from the plaster and shrinks enough to be removed from the mold.
Slip casting molds are becoming increasingly popular among potters. Slip casting allows more difficult and detailed forms to be produced at an easier level. It opens up the opportunity to create non-round forms (like the wheel produces) at a much faster rate than hand building and altering forms. It also makes the construction process simplified allowing for more time and freedom to experiment with added surface decoration.
Think of all the possibilities if you could create any kind of piece, any kind of shape, any kind of details and then create a mold form it and make it again and again and again?! Or a really simple shape that frees you up to have more time to spend drawing, decorating and creating cool patterns. The ideas are simply endless!
Many people think that slip casting is father removed from the handmade process. But in reality, slip casting wares still take a lot of time, effort and knowledge to create. First off, you need to create a prototype, therefore putting your creativity and design abilities to the test. The knowledge and skills of mold making is an art in itself and takes time to perfect. Not to mention, all the times you still handle the piece after it has been cast. You still need to trim and clean up each piece, fire and glaze. The amount of times a potter’s hand touches a piece is roughly 10-15 times after it has been made. I think that is still considered to be handmade.
Slip casting opens up a whole new realm of aesthetics from wheel thrown pottery. This can make slip casting wares especially unique. For example, different types of marbling, coloured slips, creating patterns in the mold with different coloured slips, multiple layers of different coloured slips, abstract drips and splatters, cutting and pasting slip inside the mold, the list goes on and on.
I have made a roundup of some ceramic artists who create super cool aesthetics with their slip casting molds.
1) Lenneke Wispelwey and Tiny Bagder Ceramics shows how slip casting can easily reproduce difficult and detailed pieces. Both these artists have pieces that are gorgeous in their lines and forms as well as colourways.
2) Pigeon Toe colours their slip and is able to offer products in so many different beautiful coloured clays. Adding ceramic stains to slip is much easier to mix and have consistent colours compared to wedging stains into plastic clay.
3) Laying different colours of slip while casting and then carving away is Forest Ceramic’s speciality. He uses multiple colours to cast one single piece. Using different carving tools he reveals the coloured layers within the piece.
4) Layering colours on the surface of the mold can give cool effects too. Leah Jackson demonstrates this technique. As well as showing off bold bright coloured slip.
5) Painting on slip within the mold opens up endless opportunities for patterns. Take a look at how Kelly Brenner Justice plays around with details within her molds, painting on slip and removing, as well as cutting and pasting slip decals within her molds. She shows a multitude of options when it comes to slip casting.
6) Splattering coloured slip within the mold can provide cool patterns like Inner Finn demonstrates.
7) Duck Ceramics creates coloured slip lines. Filling a squeeze bottle with coloured slip and pouring lines down the inside of your mold is how this look is created.
8) Check out Peter Pincus of Pincus Porcelain. Applying coloured slips inside the mold and then cutting away to create the beautiful patterns.
9) And we can’t forget marbling! In my own work, (Jenny Rijke) you can see the use of coloured slip and mixing to yield a marbling effect.
The options really are endless when it comes to slip casting molds and the ability to create a wide range of truly unique aesthetics.
It is hard to explain exactly what these artists all do. But, that's ok! These artists have all created a unique aesthetic for themselves. It is time for you to just use these ideas as inspiration and take some time to play with your molds in the studio and see what you come up with. Think on new things you could create even if you aren’t in the studio. I find I problem solve and scheme up ideas when laying in bed at night. You’d be surprised where you mind can take you and how you can become inspired through your own process.
I’d love to see what you create. Share your process or finished pieces with me on instagram using the hashtag #JRmolds (Jenny Rijke molds).