Melt the chocolate in a metal bowl set over a pan of hot but not boiling water. Stir the chocolate with a wooden spoon until smooth, then stir in the corn syrup; the chocolate will stiffen almost immediately. Stir until completely combined. Transfer the chocolate to a sturdy plastic bag and refrigerate until firm.
Work the Modeling Chocolate with your hands until pliable. Hand-shape the Modeling Chocolate into flowers, braids or ropes. Or pat it into a disk and roll it out to the desired thickness by hand or in a manual pasta machine and use it to make ribbons or for cutting out shapes.
The Modeling Chocolate can be refrigerated for up to 1 month.