---
title: "Use the Composer canvas"
slug: "use-the-canvas-1"
updated: 2026-08-17T12:42:33Z
published: 2026-08-19T08:43:52Z
canonical: "docs.grassfish.com/use-the-canvas-1"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.grassfish.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Use the Composer canvas

The HTML Composer canvas shows the elements of a spot and the preview.

You can use the following options on the canvas:

| **Start preview** | Start a spot preview test the spot. |
| --- | --- |
| **Preview size** | Specify the size of the canvas in the HTML Composer window using the slider, or enter the size in percent. |
| **Open configuration** | Edit configurations like [object snap](/grassfish/docs/crop-images-1). |
| **Action preview** | Start the spot preview in full HTML Wizard window mode. |
| **Fit to canvas** | Change the size of the canvas to the size of the HTML Wizard window. |