| name | squash-stretch-mastery |
| description | Use when implementing deformation effects, bounce animations, impact responses, or any motion requiring organic elasticity and weight expression. |
Squash & Stretch Mastery
The Foundation Principle
Squash and stretch is considered the most important of Disney's 12 principles because it solves animation's fundamental problem: making rigid objects feel alive. Developed in the 1930s at Disney, it emerged from observing how real flesh and rubber deform under force while maintaining constant volume.
Core Theory
Volume Preservation: When an object squashes, it must widen. When it stretches, it must narrow. This constraint creates believability—violate it and objects appear to grow or shrink rather than deform.
Force Visualization: Squash and stretch makes invisible forces visible. A ball squashing on impact shows us the floor's resistance. A character stretching mid-leap reveals velocity and momentum.
The Elasticity Spectrum
Not all objects deform equally:
- High elasticity: Rubber balls, cartoon characters, jelly (extreme deformation)
- Medium elasticity: Human faces, cloth, muscle (subtle deformation)
- Low elasticity: Wood, metal, bone (minimal but present micro-deformation)
Even "rigid" objects benefit from 1-2% deformation—it prevents the dead, mechanical feel.
Interaction with Other Principles
Timing amplifies squash/stretch: Fast impacts demand more squash; slow floats need gentle stretch. The deformation amount must match velocity.
Anticipation uses stretch: A character winding up for a jump often stretches slightly before the motion begins.
Follow-through extends it: After landing, the squash ripples through secondary elements (hair, clothing, flesh).
Domain Applications
UI/Motion Design
