A 3D printing system and methods to selectively pattern dense feedstock based on selective inhibition sintering (SIS). A sintering selectivity agent (inhibitor or promoter) is selectively deposited on a build layer according to the pattern boundary. When the layers are built-up and the part is sintered, the inhibited region remains unbound, thus defining the edge of the part. The material contain powder embedded in cohesive binder that make the adjacent layer adhere together. The build process involves forming the sheets of dense feedstock embedded binder, followed by depositing ink to promote selective sintering onto the layer. Once the build is complete, the process continues with the binder removal, sintering and finishing processes.