Line baking sheet with parchment paper.
Melt the chocolate according to the packaging using the stovetop or microwave method.
Pour the melted chocolate over the decorative mats.
Spread the chocolate in a 1/4-inch even layer.
Evenly sprinkle the decoration of your choice (sprinkles, chocolate chips, mints, rock candy) over the chocolate edge to edge.
Place the baking sheet in the freezer for 10 minutes until firm.
Allow the bark to come to room temperature before serving.
You may need more melted chocolate depending on the size of your decorative mat.