A method and system for communicating supplemental data for nodes of a graph. A visual representation of the graph is divided into portions of a computer screen. Each portion is a rectangle corresponding to a respective node of the graph. Dividing the visual representation of the graph into portions includes determining a number of pixels in rectangles displayed on the computer screen along with the graph. Supplemental data for each respective node, together with an offset distance between a reference point of each respective node and a reference point of the supplemental data for each respective node, is encoded steganographically. Fixed length attributes related to the respective node are prioritized. The attributes are encoded steganographically into the rectangle corresponding to the respective node, starting with a highest priority attribute of the fixed length attributes and continuing sequentially according to a priority of the remaining attributes of the fixed length attributes.