A designspace can combine several UFOs to make a variable font. It describes axes, masters (known as sources), instances, basic feature variation (rules), STAT information, and optionally the (subsetted) variable fonts that can be generated.
FontCreator supports both importing and exporting designspaces. It supports designspace format version 5.0 as well as previous versions. FontCreator fully supports these new subset capabilities:
•Define multiple subsets
•Change the default location
•Mark an axis as discrete
•Extrapolate axes
We recommend to use a designspace in case you want to exchange a variable font between font editors.