What are the 4 S's in ceramics?

You may have heard of the “4 S's” in ceramics and wondered what they are about. These 4 S's stand for four steps – Score, Slip, Stick, Smooth – that matter most in pottery when you want to join two pieces of clay.

Beginners in particular in our pottery classes at Formwerk Berlin often run into this frustrating situation: you enthusiastically attach a handle to the mug or add a base piece – and later it doesn’t hold and falls off while drying. In many cases this is simply because the joint wasn’t prepared properly, for example because no slip or too little slip was used. 

To keep that from happening to you, we as experts from the pottery supplier Formwerk Berlin show you the 4 S method, more or less the most important rule for joining parts in ceramics.

The Four S's in Ceramics

A tip first: Make sure both pieces of clay (the ones you want to join) have the right moisture level (still a little damp, but no longer soft) and are about equally damp before you join them. If the pieces are too dry, nothing holds anymore; if they are too wet, everything slides around. Now, step by step:

1. Score (roughen the surface): Score both joining surfaces well, going 1 to 2 mm deep with a needle tool or a knife. This roughening creates grooves where the slip can settle. Roughening matters because dry clay won't bond with itself on its own. The rough grooves provide grip so the “clay glue” takes hold properly in the next step.
   
   
2. Slip (apply clay slip): Clay slip, usually just called slip, is liquid clay, a creamy mix of clay and water that works like an adhesive. Apply slip generously to one of the scored surfaces. The wet clay mass activates the clay surface and makes it nice and sticky. It seeps into the grooves you scratched earlier and creates the connection between the two clay pieces. Without slip, two dry clay surfaces would hardly hold reliably, but with slip you get a stable bond that survives drying and firing.
   
   
3. Stick (press together firmly): Now carefully join the two pieces. Press them together evenly and with some firmness so that the slip oozes out of the seams – don't worry, that's exactly what you want. It's important not to rush, but to join the pieces slowly and calmly. The pressure makes the clay particles of both pieces interlock. At the same time you press any air bubbles out of the seam, because trapped air could cause problems later. At Formwerk Berlin we often see beginners being timid at first – but go ahead and dare to press firmly enough (as long as the clay is leather hard) so the pieces truly become one.
   
   
4. Smooth (smooth the seam): In the last step you smooth the seam. The excess slip that was pressed out when you pressed the pieces together is now wiped away and smoothed over with your finger or a damp sponge until the join looks nice and clean. This makes visible transitions disappear, and you end up with what is practically one continuous piece of clay. Smoothing isn't just for looks – it also makes sure no thin ridges of clay or cracks are left behind that could split during drying or firing. In the end you have a stable join that is so strong it's as if the parts had always been one.

Why bother? The 4 S method – Score, Slip, Stick, Smooth – is a fundamental principle in ceramics for joining separate pieces of clay securely.

In our Formwerk Berlin community, we teach every newcomer these steps because they prevent countless beginner problems. If you follow them, handles, decorative elements or attached shapes on your ceramic projects will hold much better, saving you a lot of frustration. Practice makes perfect: at first it may seem like “a lot of work for a small joint,” but believe us, it’s worth it.

So always remember to score, slip, press and smooth – then your piece will hold together securely, and you can be proud to be part of our pottery community!

Are you looking for high-quality pottery equipment at fair prices with detailed advice? Then feel free to visit our website! 😊

Have fun, the Formwerk Team!