In the fast-changing world of actionable printing, there has recently been a huge increase in the adoption of 2D barcodes for enterprise and consumer applications. The Data Matrix 2D barcode has become a primary carrier of supply chain information, most notably for track and trace. The QR (Quick Response) 2D barcode, meanwhile, has spread from Japan to the rest of the world, and is a standard means of connecting a barcode to a URL. We have previously developed a 3D (color + 2D) barcode that increases the barcode data capacity and provides branding possibilities. In this paper, we introduce the 4D barcode (color + 2D + time) as a means of using the same barcode location for multiple barcodes through time. This supports many enterprise workflows, including document lifecycles. In this paper, we consider the theory behind incremental information objects (IIOs), of which progressive barcodes are a key incarnation. We show that the set of progressive barcodes comprising a lifecycle can contain up to twice the data of the associated single-time 3D color barcode.