The Swiss Army Knife of Vector Graphics Scripting

Paper.js - The Swiss Army Knife of Vector Graphics Scripting

If you want to work with Paper.js, simply download the latest "stable" version from

You can download prebuilt packages from

As of July 2013, the recommended way to install and maintain Paper.js is through Bower for browsers, and through NPM for Node.js.

For OSX see for a tutorial explaining how to install Node.js, NPM and Bower.

For Linux see to locate 32-bit and 64-bit nodejs binaries as well as sources. It is recommended that you download directly from the nodejs site; the version available via many OS-supplied package managers is out-of-date and doesn't work with many of the packages paper uses. NPM is now included with the nodejs distribution. Once nodejs (with npm) has been installed you can install bower using the following command:

npm install -g bower

With Bower installed, simply type this command in your project folder:

bower install paper

Upon execution, you will find a paper folder inside the project's bower_components folder. For more information on Bower and to learn about its features for dependence tracking, see

The various distributions come with three different pre-build versions of Paper.js, in minified and normal variants:

  • paper-full.js – The full version for the browser, including PaperScript support and Acorn.js
  • paper-core.js – The core version for the browser, without PaperScript support nor Acorn.js. Use this to shave off some bytes when working with JavaScript directly.
  • paper-node.js – The version for Node.js. It is recommended to install this through NPM, see below.

You can also use NPM to install Paper.js for Node.js. But before doing so, you need the Cairo Graphics library installed, see

Installing Cairo and Pango on OSX:

The easiest way to install Cairo is install Homebrew then issue the command:

brew install cairo pango

Note that currently there is an issue on OSX with Cairo. If the above causes errors, the following will most likely fix it:

PKG_CONFIG_PATH=/opt/X11/lib/pkgconfig/ npm install paper

Also, whenever you would like to update the modules, you will need to execute:

PKG_CONFIG_PATH=/opt/X11/lib/pkgconfig/ npm update

Installing Cairo, Pango and all other dependencies on Debian/Ubuntu Linux:

sudo apt-get install libcairo2-dev libpango1.0-dev libssl-dev libjpeg62-dev libgif-dev

You might also need to install the build-essential package if you don't usually build from c++ sources:

sudo apt-get install build-essential

After Cairo has been installed:

You should now be able to install the Paper.js module from NPM:

npm install paper

Get the source (for building):

git clone --recursive git://

Get the source (for contributing):

If you want to contribute to the project you will have to make a fork. Then do this:

git clone --recursive
cd paper.js
git remote add upstream git://

To fetch changes from origin (your fork), run

git fetch origin

If you are working with a fork and would like to fetch from upstream, run

git fetch upstream

To update the jsdoc-toolkit submodule inside the build folder, used to generate the documentation, run

git submodule update --init

Paper.js has a couple of dependencies as Bower and NPM modules. See for a tutorial explaining how to install Node.js, NPM and Bower on OSX.

In order to be able to build Paper.js, after checking out the repository, paper has dependencies that need to be installed. Install them by issuing the following commands from the paper.js directory:

npm install
bower install

You might find that the npm command fails attempting to fetch packages needed for dependencies due to using https (the default protocol to access the npm registry). If that is the case you can switch to using http for registry access with the following command:

npm config set registry

Next you need to create minified versions of some of these dependencies. This is handled by the script inside the build folder:

cd build

The Paper.js sources are distributed across many separate files, organised in subfolders inside the src folder. To compile them all into one distributable file, you can run the script inside the build folder:

cd build

You will then find the built library inside the dist folder, named paper.js. offer two modes:

commented       Preprocessed but still formated and commented
stripped        Formated but without comments (default)

In order to minify the resulting built versions, you can run the script:

cd build

As a handy alternative to building the library after each change to try it out in your scripts, there is a helper script src/load.js that loads the library directly from all the separate source files in the src folder. The shell script in the build folder produces the paper-full.js and paper-node.js files in dist as symbolic links to src/load.js. This means you can switch between loading from sources and loading a built library simply by running or inside the build folder.

cd build

And to go back to a built library

cd build

Note that your PaperScripts examples do not need to change, they can keep loading dist/paper-full.js, which will always do the right thing. Note also that src/load.js handles both browsers and Node.js, through the handy PrePro JS preprocessing library

Since the release of version v0.9.22, Paper.js has adopted aspects of the Git-Flow workflow. For now, this just means that all development is taking place in the develop branch, which is only merged into master when a new release occurs. On this develop branch, src/load.js is used by default to load the library.

Similarly to building the library, you can run inside the build folder to build the documentation.

cd build

Your docs will then be located at dist/docs.

Paper.js was developed and tested from day 1 using proper unit testing through jQuery's Qunit. To run the tests after any change to the library's source, simply open index.html inside the test folder in your web browser. There should be a green bar at the top, meaning all tests have passed. If the bar is red, some tests have not passed. These will be highlighted and become visible when scrolling down.

The main Paper.js source tree is hosted on git (a popular DVCS), thus you should create a fork of the repository in which you perform development. See

We prefer that you send a pull request here on GitHub which will then be merged into the official main line repository. You need to sign the Paper.js CLA to be able to contribute (see below).

Also, in your first contribution, add yourself to the end of (which of course is optional).

As mentioned earlier in this article, we prefer that you send a pull request on GitHub.

  1. Create a fork of the upstream repository by visiting If you feel insecure, here's a great guide:

  2. Clone of your repository: git clone

  3. This is important: Create a so-called topic branch based on the develop branch: git checkout -tb name-of-my-patch develop where name-of-my-patch is a short but descriptive name of the patch you're about to create. Don't worry about the perfect name though -- you can change this name at any time later on.

  4. Hack! Make your changes, additions, etc., commit them then push them to your GitHub fork: git push origin name-of-my-patch

  5. Send a pull request to the upstream repository's owner by visiting your repository's site at GitHub (i.e. and press the "Pull Request" button. Make sure you are creating the pull request to the develop branch, not the master branch. Here's a good guide on pull requests:

Use one topic branch per feature -- don't mix different kinds of patches in the same branch. Instead, merge them all together into your develop branch (or develop everything in your develop branch and then cherry-pick-and-merge into the different topic branches). Git provides for an extremely flexible workflow, which in many ways causes more confusion than it helps you when new to collaborative software development. The guides provided by GitHub at are a really good starting point and reference. If you are fixing an issue, a convenient way to name the branch is to use the issue number as a prefix, like this: git checkout -tb 53-feature-manually-select-language.

Before we can accept any contributions to Paper.js, you need to sign this CLA:

Contributor License Agreement

The purpose of this agreement is to clearly define the terms under which intellectual property has been contributed to Paper.js and thereby allow us to defend the project should there be a legal dispute regarding the software at some future time.

For a list of contributors, please see AUTHORS

Distributed under the MIT license. See LICENSE.txt for details.