Agar agar powder is used in this sugar paste as a replacement for gelatin, which is more commonly used. Gelatin is typically derived from the processing of animal collagen, whereas agar agar is obtained from the sap of a Middle Eastern root. It comes in many different forms, but I prefer to use powder, which dissolves more smoothly.
Sugar paste has similar characteristics as fondant, and is handled, dyed, and stored the same way. But since sugar paste dries out more quickly, you might want to become familiar with working with fondant before tackling sugar paste. I always recommend making both fondant and sugar paste from scratch so you can better understand the ingredients.