Consumer product labels sometime include 2D machine readable codes, such as digital watermark patterns. When such label artwork is printed on a plastic sleeve that is then heat-shrunk to conform to a plastic container, the code can become distorted and unreadable. Various techniques are detailed to cope with this problem. Additionally, methods are disclosed to assess—before a heat-shrink label is applied to a product—the expected final readability of any machine readable code included in the label artwork. A variety of other features and arrangements are also detailed.