We propose an interactive system that allows common users to build large-scale balloon art based on a spatial augmented reality solution. The proposed system provides fabrication guidance to illustrate the differences between the depth maps of the target three-dimensional shape and the current work in progress. Instead of using color gradients for depth difference, we adopt a high contrast black and white projection of the numbers in considering balloon texture. In order to increase user immersion in the system, we propose a shaking animation for each projected number. Using the proposed system, the unskilled users in our case study were able to build large scale balloon art.