# Using Ribs on Moving Clay

Unit: Shaping & Forming
Topic: Using Ribs
URL: https://claybook.studio/learn/using-ribs-on-moving-clay/

# Technique and Application

A rib looks simple but using it on spinning clay takes a bit of practice. The spinning wheel amplifies any wobble in the tool; get it right and the results are beautiful.

## Holding the Rib

Hold the rib firmly but not rigidly. Your grip should absorb slight vibrations without clenching. The rib edge that contacts the clay should be smooth. Check for chips or rough spots before using.

## The Outside Rib

To shape and smooth the outside wall:

1.  Hold the rib in your outside hand, pressing the curved or flat face against the clay wall.
2.  Your inside hand provides counter-pressure from inside, supporting the wall.
3.  Move the rib slowly upward as the wheel spins. The inside and outside hands move together, as in a normal pull.

This is one of the most powerful shaping moves in throwing. You can dramatically alter the profile of a bowl in seconds.

## The Inside Rib

A rubber or flexible rib on the inside is used to:

*   Smooth the interior surface of a cylinder or bowl.
*   Remove the concentric ridges left by fingertips.
*   Compress the inside of a plate floor.

Press gently and move slowly from the center outward (for floors) or from the base upward (for walls).

## Common Mistake: Digging In

If you press too hard or at the wrong angle, the rib edge digs into the clay rather than gliding. This leaves a groove that is hard to remove.

**Fix**: Tilt the rib so the leading edge is raised slightly: the contact is made with the face of the rib, not the edge. Think of it like a snowplow blade.

## Pro Tip

Use a metal rib at the very end of throwing to do a final compression pass on the outside wall. It removes surface moisture and fingerprints and leaves the clay looking crisp and refined.

## Rib Control Drill
Practice with one cylinder:
* One pass for shaping only
* One pass for smoothing only
* One final pass for compression only

Separating intent by pass improves control and consistency.

## Down the Rabbit Hole

The smooth, compressed surface a metal rib produces is a mild form of the same principle behind [burnishing](https://en.wikipedia.org/wiki/Terra_sigillata), where ancient Roman potters aligned clay particles to create a natural sheen without glaze. Developing consistent rib technique is largely a matter of [muscle memory](https://en.wikipedia.org/wiki/Muscle_memory), and most experienced throwers report that the tool eventually feels like an extension of the hand.

## Check your understanding

### Question 1: What causes a rib to dig a groove into the clay instead of gliding smoothly?

- [ ] A. Moving the rib too slowly
- [x] B. The rib edge digging in instead of the face gliding
- [ ] C. Using a wet rib on dry clay
- [ ] D. The wheel spinning too fast

Tip: Pressing the leading edge into the clay rather than the face. Tilting the rib so the face makes contact fixes this.

### Question 2: When using a rib on the outside wall, what must the inside hand do?

- [ ] A. Rest on the rim
- [x] B. Apply counter-pressure from inside the wall
- [ ] C. Hold the sponge
- [ ] D. Nothing, it is not needed

Tip: The inside hand must provide counter-pressure from inside, supporting the wall so the rib does not push it inward.