---
title: "Acetate"
space: "Dictionary of Stop-Motion"
url: "https://erpnext-urs-tqc.v.erpnext.com/dictionary/acetate"
updated: "2026-11-10"
---

# Acetate  
<a title="Janke at English Wikipedia, CC BY-SA 3.0 &lt;https://creativecommons.org/licenses/by-sa/3.0&gt;, via Wikimedia Commons" href="https://commons.wikimedia.org/wiki/File:File-Inkandpaint.jpg"><img width="256" alt="File-Inkandpaint" src="https://upload.wikimedia.org/wikipedia/commons/d/d9/File-Inkandpaint.jpg?20210620211731"></a>

<a href="https://commons.wikimedia.org/wiki/File:File-Inkandpaint.jpg">Janke at English Wikipedia</a> 

<a href="https://creativecommons.org/licenses/by-sa/3.0">CC BY-SA 3.0</a>, via Wikimedia Commons

## Definition  
Acetate is a clear plastic sheet (cellulose acetate) once common in film and animation. In stop-motion, it shows up as cell material, overlays, or practical effects that require transparency.  

## Context  
On a puppet stage, acetate can be used for in-camera tricks: false reflections, smoke layers, or transparent props. Historically, it was the base material for 2D cel animation. In VFX, painted acetate sheets were sometimes used for mattes or optical composites.  

**Related:** [Cel Animation](/dictionary/cel-animation), [Matte](/dictionary/matte), [Overlay](/dictionary/overlay), [Transparency](/dictionary/transparency)  

## Examples  
- A sheet of acetate angled in front of the camera to fake window reflections in a miniature set.  
- Painted clouds or smoke on acetate, placed between camera and puppets, to add depth.  
- Traditional cel animation, where characters were inked on acetate cels and stacked over backgrounds.  

## Notes  
- True cellulose acetate has mostly been replaced by safer plastics, though the word “cel” is still used.  
- Heat from stage lights can warp acetate, bending reflections or painted overlays.  
- Acetate film stock degrades over time, producing “vinegar syndrome,” a strong smell and visible shrinkage.  

## Media  
- **Diagram:** a stack of acetate cels layered over a painted background.  
- **Clip:** cel overlays combined with stop-motion footage.