In some embodiments, a design verification system is provided that is configured to perform actions for ensuring fabricability of a segmented design. The design verification system searches a proposed segmented design for a paintbrush pattern to determine a positive paintbrush loss, and searches for an inverse paintbrush pattern to determine a negative paintbrush loss. The design verification system combines the positive paintbrush loss and the negative paintbrush loss to obtain a total paintbrush loss that indicates whether or not the proposed segmented design is fabricable. If the total paintbrush loss indicates that the proposed segmented design is not fabricable, the design verification system updates the proposed segmented design based on a gradient of the total paintbrush loss.