A latent image developing system, a novelty kit, and an ink composition for printing latent images on a substrate. The latent image developing system includes a first substrate containing a colorless image deposited on a first surface thereof. A developer component is provided that is reactive with the colorless image to provide a visible image. The developer component is selected from a developer instrument, a developer finger paint, a developer coating on a first surface of a substantially transparent substrate for adhesive attachment to the first substrate, and a combination of one or more of the developer instrument, the developer finger paint, and the developer coating. The latent image developing system optionally includes, an image blocking instrument for concealing at least a portion of the visible image. The image blocking instrument includes a blocking composition applicator and an aqueous mixture of blocking composition and water.