This Spiderman icing image is an A4 sized rectangle. Completely edible, made from a thin icing sheet which softens into your frosting.
To place on buttercream:
Cover your cake with buttercream and smooth. Carefully remove image from backing (place in freezer for 5 mins if needed to help with removal), then place on top and press down.
To place on fondant:
Cover your cake with fondant. Using a slightly damp brush, dampen the area the image will sit on, or alternatively, use piping gel. Remove image from backing as above and press and smooth.