Drawing in Three Dimensions
Slip trailing is the pottery equivalent of piping icing onto a cake. You squeeze liquid slip through a narrow nozzle to draw raised lines, dots, and patterns directly onto the clay surface. The slip dries in place, creating a three-dimensional texture that remains after firing.
Why It Stands Out
Every other decoration technique covered so far is essentially flat: it lives on the surface. Slip trailing literally rises above the surface. The raised lines and dots catch glaze differently than the surrounding clay, creating depth and visual richness in the fired piece.
Traditional slipware pottery (especially English and American folk pottery) relied heavily on slip trailing for its distinctive flowing patterns.
The Slip Trailer
The tool is called a slip trailer: a small rubber or plastic bulb with a narrow metal or plastic nozzle. You fill it with slip, squeeze gently, and trail the nozzle across the pot surface.
- Bulb size: Smaller bulbs give more control; larger ones hold more slip.
- Nozzle diameter: Narrow nozzles produce fine lines; wider nozzles produce bolder, more gestural marks.
Preparing the Slip
Slip for trailing must be thicker than brushing slip, approximately the consistency of thick honey or cream. Too thin and it runs and spreads; too thick and it does not flow from the nozzle.
Test the consistency by trailing a line on a piece of newspaper. It should hold its raised shape without spreading, and flow smoothly without sputtering.
Trailing Setup Checklist
Before decorating:
- Sieve or stir slip to remove lumps
- Burp air from trailer bulb
- Run a short test line on scrap
Good setup prevents splatter and broken line flow.
The Bigger Picture
Slip trailing has deep roots in European folk pottery, and the Wikipedia article on slipware showcases centuries of trailed decoration from English chargers to Roman Egyptian cups. The French term for this technique is barbotine, which covers both piped slip decoration and the broader tradition of working with liquid clay as a decorative medium.
