Superpolator3 can read and write two slightly different file formats. This page describes the differences and what to expect.



This is the Superpolator3 native file format. All data is supported. It stores the axes, the sources and the instances. It also stores rules, colors for various items, and various settings for the window like preview text.



This is the format used by MutatorMath and some functions of FontTools. Earlier versions of Superpolator could only export designspaces. Now it can also read, but with some caveats. The basic geometry of the designspace can be imported and exported.

  • Rules are not exported to designspace. Rather, the results of the rules are. So if an instance is in a location that has an active rule, that rule is executed and the instance shows the results.
  • Special masters for glyphs (used to record the results of rules) are not imported into Superpolator
  • Color settings for masters and axes are not exported. Superpolator will try to match default colors to the incoming axes but that might not be the same.
  • Preview text and text snippets are not exported.
  • Axes in a designspace may contain tables that describe the transformation of user-space to design-space. These tables are not supported in Superpolator, but they work in MutatorMath.

What does that mean? For most of the projects everything will be easy. If you start from an existing Superpolator document and export to designspace, this will be a new file. So you can always go back to the original.