Methods, systems, and computer programs for multi-tool additive manufacturing include a method including: slicing a received model into a series of layers; determining one or more separation starting points, each being a location of two adjoining portions of the model that are to be manufactured by respective additive manufacturing robots; and determining an offset for each of the one or more separation starting points in each layer of the series of layers based on a threshold acceptable print time, each offset in a layer determining a seam location in the layer that is different from a seam location in at least one adjacent layer in the series of layers, and seam offsets determined for the series of layers increase an estimated print time, for manufacturing of the series of layers by the two or more additive manufacturing robots, to no more than the threshold acceptable print time.