The properties of fondant and gum paste (also called sugar paste) are quite similar.  Fondant is typically softer when compared to gum paste, making it ideal for molding into unique shapes. Gum paste on the other hand typically is harder, which allows for harder creations when firm and dry. 

Inkedibles offers a version of fondant that is a perfect replacement for BOTH fondant and gum paste.  It is soft enough to be flexible for unique shape creation, yet it also firms up to hold on to the shape you create.