If you’re looking to create beautiful ceramics without the use of colored glazes, then agateware is a brilliant way to do it. Agateware is basically created from the mixing of two different clay bodies of different colors to produce a marble effect.
The method of marbling clay was first recorded in China during the Tang Dynasty (from 618 to 907 CE), although the technique didn’t make it to Europe until the 17th century.
Agateware later and most famously found prominence in the 18th century with Britain’s famous Stoke-on-Trent potters, and was notably favored by world-renowned potter Josiah Wedgewood. The name agateware is said to originate from the similarities it bears to agate stone. Agate stone, a semiprecious stone, reveals many swirling layers of varying colors when it’s cut open, which is what agateware clay looks like when it's been mixed. The ceramics technique has several different names across the globe and is also known as scroddled ware, which is described as "mottled pottery made from scraps of differently colored clays." In Japan, the technique is called neriage or nerikomi, the difference between them being that neriage refers to agateware which has been thrown on the wheel and nerikomi is agateware that’s been hand built.
How to Prepare Clay for Agateware
The ancient technique of agateware has seen a real revival in recent years, with potters creating interesting and varied works, each completely individual. To start making agateware, you’ll need several different colored clays (the amount of different clays is completely up to you, dependent on the effect you want to go for, but two different clays is usually sufficient). Traditionally, a white clay is used combined with a darker clay (to give the marbling a real contrast). Note that it’s important to use clays which all have a similar firing temperature. Once each of the clays you want to use is wedged and ready, slice them into blocks and stack them in layers. To get a really good mix, and to ensure the colors don’t look too sludgy, aim to make the block of white clay around two or three times thicker than the darker clay. Continue to layer up the clays until you’re ready to carefully roll it.
How to Use Agateware in Molds
You can simply roll out the clay and press it into your mold, or you could make the pattern more intricate. Once you’ve rolled out the clay, cut it into equally sized horizontal strips (you can make them whatever width you'd like). Then you can take each slice and swap the strips around, changing their swirling patterns to create a more abstract effect.
If you want a more circular pattern, then layer up your clay in the same way but roll it into a tube shape and slice circles off of it. Be careful when you’re rolling it out, so as not to merge the colors too much, as they become murky. Make sure you have a large enough piece of your marbled clay (you can join them neatly in a patchwork of squares, making sure the pattern is carefully pieced together if you don't have enough) and then push the clay into your press mold.
How to Create Wheel Thrown Agateware
Retaining the marble effect when throwing on the wheel can be a little trickier, so it’s important to work as quickly as you can, centring the clay as quickly as possible, and avoiding pulling the clay up too many times. Rotate the wheel as slowly as you can and try not to handle the clay too much. Another way of preparing agateware clay for the wheel is to roll two medium sized balls of different colored clay, one white clay and one darker. Use a wire to cut each of the balls into quarters and then swap two quarters, so each ball has two white clay quarters and two dark clay quarters (they'll look a little like juggling balls). The balls are then ready to throw and will give a great marble effect.
How to Glaze Agateware
Once you’ve made your ceramic piece, either wheel thrown or hand built, and waited until it’s leather hard, you can buff the ware to get a high shine natural polish. The patterns created are usually beautiful enough to be left without any glaze (a dark color glaze would run the risk of covering your pattern completely). However, a clear glaze can be a good way to create a high shine without buffing. If you leave the piece just buffed and not glazed then it will be purely decorative. Adding the clear glaze or a light glaze to the ware will make your piece food safe.