# Darting, Indenting, and Combining Alterations

Unit: Advanced Throwing Techniques
Topic: Altering Thrown Forms
URL: https://claybook.studio/learn/darting-indenting-and-combining-alterations/

# Darting: Creating Facets with Pressure Points

Darting means pressing inward at specific points around a form to create distinct indentations, like pushing your thumb or a rounded stick into the side of a vessel to leave a concave dimple. Multiple darts around the circumference create a rhythmic, petal-like pattern.

## How to Dart

*   Decide how many darts you want: three, four, five, or six evenly spaced around the form.
*   Mark the positions lightly with a needle tool so they are evenly spaced.
*   Use your thumb or a rounded wooden tool to press inward at each mark.
*   The walls opposite the dart will push outward slightly: this is normal and creates the convex bulge between darts.
*   Work all darts gradually rather than pushing each one fully before moving to the next.

## Indenting Rims

The rim of a bowl or vase can also be altered by gently pinching or pressing inward at intervals to create a lobed or scalloped top edge. This works best on forms with slightly thicker rims.

## Combining Techniques

Squaring and darting can be combined. A squared vase with darted corners has both angular structure and organic softness. A squared mug with a single dart on two opposite sides creates a comfortable thumb grip.

## After Altering

Once altered, let the form continue drying under a light cover to even out the moisture. Altered forms can dry unevenly: the thicker areas retain moisture longer and can crack where they meet thinner sections if dried too quickly. Slow, even drying is essential.

## Down the Rabbit Hole

The combination of wheel throwing and post-throwing alteration is a defining feature of much contemporary [studio pottery](https://en.wikipedia.org/wiki/Studio_pottery). Understanding how [thermal expansion](https://en.wikipedia.org/wiki/Thermal_expansion) affects clay during drying and firing helps explain why altered forms with uneven wall thickness require extra care at every stage of the process.

## Common Mistakes and Quick Fixes

*   **Deep single-pass darts**: Build depth gradually around the full circumference.
*   **Skipping spacing marks**: Mark dart positions first for visual rhythm and balance.
*   **Ignoring thickness differences after altering**: Dry slowly under cover to reduce cracking.
*   **Combining too many alterations on first attempt**: Master one technique before layering many.

## Practice Exercise

Create a four-piece alteration study set: one darted, one squared, one rim-indented, and one combined. Dry and fire together, then evaluate which profiles stay strongest and most expressive. Use this as your personal altered-form baseline.

## Check your understanding

### Question 1: When darting a vessel, why should you work all darts gradually rather than completing each one before moving to the next?

- [ ] A. Gradual passes allow the clay to dry between darts
- [x] B. Working all darts gradually keeps the form balanced and prevents uneven distortion
- [ ] C. Deep darts are not possible in a single pass due to the clay's resistance
- [ ] D. It makes no difference: work each dart to completion before moving on

Tip: Working all darts gradually keeps the form balanced as you go. Completing one dart fully before moving to the next can distort the form unevenly and make it difficult to correct.

### Question 2: Why is slow drying under cover especially important for altered and faceted forms?

- [ ] A. Altered clay is chemically weaker than thrown clay and needs more time to cure
- [x] B. Uneven wall thickness from alterations creates drying tension between thick and thin sections, causing cracks
- [ ] C. Slow drying helps the clay 'remember' the altered shape before firing
- [ ] D. Drying speed has no particular effect on altered or faceted forms

Tip: Altering and faceting create uneven wall thickness: pressed or indented areas are thinner, while undisturbed sections remain thicker. If the outer surface dries much faster than these thicker interior sections, the tension between them causes cracking. Slow, even drying eliminates that stress.